I could be wrong, probably am wrong, and guarantee either way someone will tell me I'm wrong. That said, I lived full time (spring summer fall winter) in a RV off and on for about 5 years as a tramp powerline worker. Mostly in parks, but sometimes in makeshift parks that were set up in open spaces and electricity, water, and sewer were via generator, tanks with pumps, and weekly visits by the poop pumper trucks.
By and large I did it with a 2013 Arctic Fox 25Y bumper pull and a 1997 Alpenlite Riviera 29 5th wheel.
The 25Y was nice but the big picture window out back was not fun during the dead of winter as it is a big heat sucker upper and ended up getting blocked off by a thermal blanket so I missed the pretty snow scenery. Some days it wasn't below freezing and it could come down to reveal winter wonderland. Otherwise it was fine--I don't know the specifics as to what makes the Arctic Fox trailers so good at handling true winter temps in places like North/South Dakota, Wyoming, and eastern Montana but the water tank and plumbing are ran inside the trailer for the most part and the roof and bottom are insulated well. I did build my own skirting around the outside which is nice both for winter heat retention and summer heat avoidance.
The Alpenlite as well did great, just bigger space so more expensive to heat and cool. Again, with the big picture window at the back, and I built skirting. I made both trailer's skirts the same, out of plywood. I still firmly believe Alpenlite manufactured the 'best' 5th wheel travel trailer you could buy, pre 2000. Even today they are better than most still after 20+ years. I don't have a need for the 5th wheel but I'd highly recommend looking for a well preserved Alpenlite if you're in the market. I have no affiliation to this one, just found it on a google search, but it's near identical to what I had, just a 2000 instead of a 1997.
https://www.rvtrader.com/listing/2000-Alpenlite-M-29RK-RIVIERA---5023782293?cmp=rvreviews-listing
Honestly, if my coworkers practiced a little proactiveness, all the RVs seemed to do ok. The biggest issue with most of the ones that failed was poor insulation underneath, exposed water lines and water tanks, and terrible windows. The folks who sealed them up ended up with ice on the insides and a lot of moisture. The Fox and the Alpenlite I was able to run my "fantastic fans" quite a bit and circulate the air, and I used a dehumidifier. Honestly, in the 2 years with the Alpenlite and the 3 years with the Arctic Fox I had zero winter time related failures of anything. No leaks either but I gave them a thorough inspection each spring and fall, and touched up things that looked questionable.
Full disclosure I did not really care what my power bills were as my per diem was more than covering my pad rent and whatever my power bill was what it was. Between 60-175 a month at most places I stayed at was the norm for electricity and I ran larger propane tanks but rarely used them, just ran the electric side mostly since we were normally on full hookup.
A couple brands I remember that were doing well aside from aforementioned Nash/Fox/Outdoors RV and my Alpenlite were Grand Design, Nu-Wa Hitchhikers, Dutchmen, Airstream (and the variants like Avion, etc) and honestly once the bugs all got worked out a buddy had great luck with his Keystone Montana. By and large though most people did say that my Arctic Fox seemed the most comfortable and I'm a simple jack type, so that's where I sort of start and stop when shopping for a towable RV anymore.
I will say if you can make it work that a motorhome is a better winter time RV than anything you tow behind you. For various reasons, a major one being the weight is not as much of an issue so they can build with thicker walls and materials, more insulation, and heavier duty components.
The 25Y is listed dry weight as 6,640 lbs. I know from factual usage experience and ownership since 2013 that mine actually weighs 7,020 and full of stuff to live full time pulls down the road around 9,000-9,200. My 4wd F-550 shop truck feels it and both my Ram 2500 and OBS F-series aren't exactly happy it's back there.
The Alpenlite was listed at 9,043 lbs dry but actually weighed in at 9,500 and fully loaded with more crap--bigger space more crap--it was an 11,000 lb trailer...
..but again remember I'm full time so there are tools, mountain bikes, cases of beer, heavier than normal RV furniture, kayaks, TDR magazines, Geno's maintenance kits, dead hookers in the closet, shovels, etc.
That said, they all suck compared to even a crappy house. ATCO shacks are much better.