Key word on Bigfoot
: SOME are four season (some aren't). You can bet a four season trailer will be heavier than its 3 season competition.
As far as terrain, depending on where in the Blue Ridge Mountains, there are plenty of steep grades. Where I live north of you, I can't go a block without going up a grade, and less than a mile and I am into a steep grade. People that have attended the Cherokee Rally
can vouch for the grades around here.
Many avoid the four season problem by heading south when it gets cold. Most of the three season rigs have at least a portion of the plumbing, black and gray water tanks, exposed to the weather. And mine also has the water tank exposed. Simple solution if you stay in a colder area is to get really good at winterizing your trailer. In my area, we will get cold snaps, but its not too long, say a week or so. People have put temporary skirting around the bottom of their trailer, along with some heat, to keep pipes warm.
On towing capacity, its a lot more complicated than just the raw tow rating. You also have tongue weight
limits, payload limits, gross combined weight
limits, and more. And yes, unless your Pilot came with a factory tow package, you will need stuff under the hood.
I know several people living full time in campers. I can't think of a single one that has a four season trailer. But all of them move during the winter months.
Also realize on weight
, its a lot different packing your rig for a week of camping than living full time. Expect to be on the high end weight wise, unless you have access to a storage unit.