The most important thing about using an RV in the winter is your brain. Keep it engaged all the time even when you are stopped.
I strongly suggest that you keep looking at floor plans. If it works, it has been done. If it doesn't work, there are still a few out there. Also, as it is your first, search the used market. You can save a lot of money and as it is unlikely it will be your last, you will have formed some important impressions of what you like and do not like.
We often travel/camp in cold weather. Probably colder than you are anticipating. Always anticipate cold and bad weather. If you have to hold up a day and wait until the weather breaks, just keep the heat on and do that. Have an extra day's provisions and fuel always. Let the crazy ones go have their own accidents and go home.
Most newer RVs are insulated well enough, but if you are running in cold, you have to be aware that water lines can freeze and be damaged, so be ready to deal with that should the need arise.
Know what temperature your electric heat can handle. You may not able to do much on an extension cord when visiting relatives.
A lifelong waterman and his bride going dry places for as long as the fuel money lasts.