I see you asked another question about a Rockwood and I answered that one based on that question..
As far as my Rockwood, it has 12v heated tanks and a covered bottom...
I don't ever plan on doing any kind of 'winter' camping with it, so no issue with me on it..
I have had it out in really hot weather and in some mid 40* nights and it gets HOT inside when it's hot, so the A/C is on to keep it 'comfortable' inside and it gets COLD on those cold nights and I had to run the furnace to keep it 'comfortable' even under the bed covers...
Like I said, I don't camp when it's 'freezing' out.. But, when it gets chilly, I'll do what I need to do.
No, the Rockwood is NOT a true "4 season" trailer IMO... Sure, you can probably get thru freezing weather with it.. But, not me! :)
Good luck! Mitch