You answered most of Brett's questions, but are you handy and capable of doing your own repairs? Also, new only or used... if used how old? At 40' you are looking at a Diesel Pusher... DP. For it to handle cold weather you need a mid to high end DP with AquaHot heating.
By clicking on "Class A Motorhomes" above your first post you can get to Johnny T's Sticky "First time buyers"... well worth reading. There is also a lot of info hidden in the "Advanced Search" above and then in the second area click on "Class A" before searching. I'd search for things like: AquaHot, CCC, 7 year old tires, RR10S, Girard or Girrard awning, heated tanks.......
At 40' it's hard to get enough CCC for Full Time use without having two axles on the rear... a tag axle. There is a "Full time RVing" section in the box at the top right. There is also a "Snowbird" section at the bottom of the same box which will help with where to go in the winter.
Plenty of good free advice with a little searching.
This post is my opinion (free advice). It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose.
Sold 04 Dynasty to our son after 14 great years.
Upgraded with a 08 HR Navigator 45’...