Both great trailers, but very different. The
Oliver is narrow for better towing and aerodynamics, but not as spacious and less storage. Lots of high-end materials and that sleek, gelcoat interior (don't know if that's what I'd want in the winter...). Not as many used units out there, so prices are high.
Bigfoot is 8' wide and boxy with a more traditional (but well built) RV interior. Bigfoot's been making them a while, so I've seen some nice used units at much more affordable prices than any
Oliver. I'd have no hesitation buying a 10-year-old Bigfoot.
Don't know what kind of winter Alaskan camping you're thinking about- it's a big state- but even the best 4-season trailers are not well-suited for extreme cold. Unless you have an unlimited supply of free
propane...