I live near Ottawa, familiar with your climate challenges.
Fresh air coops can work here but require a design that ensures the birds have an area with no drafts both when on the roosts and during day time hours. I am not convinced that your design can accomplish this.
As has been pointed out, the likelihood of moving a 10' x 8' tractor every few days is, IMHO, not high. You, for sure, are not going to be moving it in the winter.
Your neighbour's suggestion that chickens can stay in a small coop over the winter is wishful thinking. (The lady who cuts my hair assumed this, ended with bullying and a couple of dead hens.)
I also think that you have not given enough thought to yourself and the daily maintenance that chickens require. Things like:
- access for you into coop (needs to be easy especially in the winter and preferable to the inside so you do not have to shovel snow to access things like eggs & poop & food/water)
- water in the winter; without electricity water will freeze in a few short hours so you will be carting water multiple times a day
Your conclusion re a conventional coop & run is encouraged, if it were me I would also have a solid roof over at least a portion of the run.
Given your questions and the design I am going to assume this is your first experience with chickens. I am six years into my experience and am still modifying things to optimize my coop & run; this even though I researched for close to a year and found a design that suited my goals.
Designing from scratch with no experience is an invitation to frustration and failure. You want to enjoy the experience or you will soon abandon the effort.
I strongly encourage that you find a proven design that fits your needs. Rather than spend time designing something that won't work I would create a list of your ideal needs/desires (eg space for 6 chickens, heated water, ability to collect eggs with getting rained on or having to move snow, etc.). Once done post it here and ask for input. Use these to find a design that fits.