My chickens survived last night pretty well. When I got home I just needed to give them some water and about 4 cups of scratch, so they can generate some heat for tonight. It is currently 10.2 in the coop at the moment and it is -12 outside. I did get six eggs today. down from 8 the day before. When it gets this cold they like to cram themselves into the nesting boxes and share their heat. I just dont have the heart to shoo them out.
I am starting to save more eggs for the wine-o-bators next hatch. The test eggs went on lockdown this evening. I candled also. Everything looks good. I only had one quitter. So 14 are going into lockdown. I will update and let everyone know when the chicks start to hatch in my experimental home made incubator. I do need to modify a couple of things. I need a way of getting water into the water tray without opening the door and I need to place a wire grid on the hatching surface of the hatching tray, to hold the eggs in place, as the eggs roll around too much for my liking.
On a different note. my furnace went out last night. It got down to 50 in the house before I realized it. The incubator didn't miss a lick. It maintained the temp inside really well. It was reading 100 when I checked on it. I had to fire up the pellet stove that I installed in the basement this fall. This raised the temp in the house to 62 in no time, even though it was -12 this morning. Its always good to have a back up plan.
Wow, thank goodness you have the pellet stove!
For eggs in the hatching tray, a couple of options, if you have room for hatching upright, would be the bottom half of egg cartons, or plastic egg trays like this

I have a couple of these I use, and if I have more than 30 going to hatcher I add a carton bottom. I like that they can be washed and disinfected; after I use them I just wash in soap and water along with the plastic tray that holds water, the screen that covers it, and the plastic shelf liner that I put over the screen so the chicks get better footing. All these items plus the styrofoam bottom of the hatcher get washed and sprayed with Oxine after every hatch, air dried, then put back together the night before I'm going to start it back up. These plastic egg trays are on ebay, currently $2.99 each plus shipping. I don't sell them, I just bought them after someone recommended them to me, and I like them. Bob hates them, he is convinced I will lose chicks getting their legs caught in the holes. It hasn't happened yet, and I've used them for 5 or 6 hatches now. I had the same concern but the person who recommended has used for many more hatches than I have and has not had chicks get caught in them.