I have 2 vintage Canvas Wall Tents for sale. Both in Good condition. Both were treated with Water Repellent a couple summers back. Both of these tent we have used in all 4 seasons. A small electric heater is all it take to keep these tents toasty.

1. Coleman, I think, 6x8 (maybe a little bigger) zippers work well except the outer most flap, zipper track is good but missing the pull thingy. $200 Or Best Offer

2. Sears 3 room divided wall tent, this thing is massive, 8x16 I think, with a "porch shade cover", when the rain stops I will set it up and snap pics and get good measurements. $300 or best offer
Similar to this pic I found on the net (this is not my tent, mine is nicer)