I think of it as the ability to camp while below 10F and still be able to use the water and sewage tanks without a problem.
Extra insulation is a given. Hopefully the manufacture included heated area around the tanks, and given some thought to how to live in the RV while it is 10F outside. Sufficient furnace size that it will not need to run 40 minutes or more each hour, and such.
Those in the south, they might agree that dual air conditioners and perhaps some fantastic fans should be included in the 4 season package.
50 amp electric service should also be included, so that electric heaters, electric fireplace has some place to power up, without worry about the main circuit breaker tripping on a cold night, or when 2 A/C are running and you want to cook something like coffee and run the 10 amp microwave at the same time. . .
Fred.
Money can't buy happiness but somehow it's more comfortable to cry in a
Porsche or Country Coach!
If there's a WILL, I want to be in it!
I havn't been everywhere, but it's on my list.
Kangen.com Alkaline waterEscapees.com