I believe what Ed was saying is you don't need any wire on the ground "inside" the run... Let the earth do what it's been doing for an eternity. The chickens will mix all of that "stuff" into the soil in their day to day scratching and dust bathing. All you have to do is occasionally add more "stuff" to the mix, either green (for moisture if too dry) or brown (pine chips, dead leaves, etc) if too wet. no sand, no DE, just nature: good microbes and worms. If they aren't 'turning it" to your satisfaction, just throw in a handful of BOSS or scratch grains and watch the digging and mixing commence! You can do the same thing inside the coop, if it's large enough, and you prefer to NOT have a work/cleaning intensive chickeneering experience. The only issue/problem with doing it (deep litter) inside is unless you add some good dirt as a starter, you won't have mother earth working with you. Done properly, there's little to no smell, little to no effort, and you end up with excellent garden ready compost. Pure chicken poop is so nitrogen rich, if applied directly on most plants, it will burn/kill them. As the level of the run deepens, at some point down the road, you can move the top layer aside and remove some of the deep rich soil from underneath, and have the best yard/garden in the neighborhood. All natural, no chemicals.
What you should (could) do to prevent diggers is place an apron of wire around the outside of the run, laying on the ground, then covered with dirt/gravel/rocks/pavers, etc. I used 2" x 4" welded wire fencing. The only potential downfall to that is if you have weasels/ferrets/mink in your neighborhood as they can fit through extremely small holes/openings and are excellent diggers. They will make a hole right through 2x4 fencing and be in the run in very short order. The one up side is they attack mostly at night, when your birds would most likely be inside the coop, secured from outside access. Keep in mind a weasel or stoat can fit through an opening about the size of a quarter. That's why some recommend burying 1/2" hardware cloth as the apron.The apron should reach out about 2 feet from the sides as not many animals will be smart enough to back up 2 feet and re-start digging. Alternatively, you could dig a trench and place the apron down vice out, but that is one heckuva lot more work (you may ask me how I know this). You can attach the apron to the bottom of your existing enclosure fencing with hog rings or simple baling wire, or you can cut the "head" run (horizontal/top wire) of wire off, and then bend the now available runners (the vertical wires of the fencing) to attach it. Here's pics of mine:

When you say it gets cold, and then mention "removing (closing it up) it" for insulation... it caught my attention. If you live in an area where temps go below freezing, unless you intend to heat the coop to maintain temps inside above freezing, you don't want to close it up at all, but rather OPEN it up. You want the inside temperature to equalize with the outside temp to prevent moisture condensation inside. the birds breath and poop over night creates a LOT of moisture. You'll be surprised. moisture at temps below freezing in an enclosed environment are what causes frost bite and freezing of extremities (combs, wattles, toes). You want as much positive air flow and venting as possible while trying to keep direct drafts off/away from the roost. Ideally low/near floor openings for in coming air and a LOT of open area/space above/high for the warm moist air to escape. This is especially critical in the winter. The chickens have year round down coats on (except when they molt of course), and they'll fluff them up and settle down and be quite content as long as there's no breeze "lifting their knickers" while they try to stay warm.
Hope this helps.
What you should (could) do to prevent diggers is place an apron of wire around the outside of the run, laying on the ground, then covered with dirt/gravel/rocks/pavers, etc. I used 2" x 4" welded wire fencing. The only potential downfall to that is if you have weasels/ferrets/mink in your neighborhood as they can fit through extremely small holes/openings and are excellent diggers. They will make a hole right through 2x4 fencing and be in the run in very short order. The one up side is they attack mostly at night, when your birds would most likely be inside the coop, secured from outside access. Keep in mind a weasel or stoat can fit through an opening about the size of a quarter. That's why some recommend burying 1/2" hardware cloth as the apron.The apron should reach out about 2 feet from the sides as not many animals will be smart enough to back up 2 feet and re-start digging. Alternatively, you could dig a trench and place the apron down vice out, but that is one heckuva lot more work (you may ask me how I know this). You can attach the apron to the bottom of your existing enclosure fencing with hog rings or simple baling wire, or you can cut the "head" run (horizontal/top wire) of wire off, and then bend the now available runners (the vertical wires of the fencing) to attach it. Here's pics of mine:
When you say it gets cold, and then mention "removing (closing it up) it" for insulation... it caught my attention. If you live in an area where temps go below freezing, unless you intend to heat the coop to maintain temps inside above freezing, you don't want to close it up at all, but rather OPEN it up. You want the inside temperature to equalize with the outside temp to prevent moisture condensation inside. the birds breath and poop over night creates a LOT of moisture. You'll be surprised. moisture at temps below freezing in an enclosed environment are what causes frost bite and freezing of extremities (combs, wattles, toes). You want as much positive air flow and venting as possible while trying to keep direct drafts off/away from the roost. Ideally low/near floor openings for in coming air and a LOT of open area/space above/high for the warm moist air to escape. This is especially critical in the winter. The chickens have year round down coats on (except when they molt of course), and they'll fluff them up and settle down and be quite content as long as there's no breeze "lifting their knickers" while they try to stay warm.
Hope this helps.