Although my garage is heated, my circumstances are very similar to yours. My car lives next to a daily driver that comes and goes every day and drops all manner of salty gunk all over the floor.
Here is what I do:
Fresh oil (cheap stuff) because I change it again in the spring. Don't forget the ZF
Thorough cleaning, everywhere
complete wax
obviously critical - make sure your coolant mix will withstand winter temps.
I do not remove the battery but I attach a battery maintainer (not a trickle charger) that cycles the charge up and down. I have been doing this for years with nary a problem
I do not jack mine off the floor but I do add 10 psi into the tires
Treat all the weather stripping with petroleum jelly or equivalent (tie rod boots too)
You already mentioned full tank and stabilizer (make sure to run the car 5 minutes to fill lines and carb)
I use a top quality car cover (personally, I would not wrap mine in a vapour barrier plastic bag. No way for condensation moisture to escape)
I have never done it, but I do like the idea of putting a barrier down to cover the floor
A lot of car guys say, don't touch, but I fire mine at least once a month, usually more often and let it warm to full temp
I also put it in gear and roll it in and out of the garage a few times. I chalk the tires to get a different spot every time
I tinker and fiddle with mine all winter to help ease the withdrawl symtoms
I,m sure others will add some stuff I missed
Doug M