An alternative you may want to at least consider is a Pilot. The 4WD version is rated to 4500/450, it has more room inside, and it should give equal or better fuel mileage. Either of the trailers you mentioned would be a comfortable tow, whereas the larger might be a stretch for the Tribeca, since it's probably pushing 3000#. The AWD system is not as good as a Subaru, since it can only do a 50-50 front-rear torque split (vs. 10-90 in a Subaru), but it does have a locking feature to hold the 50-50 split in slippery conditions. Anyway, surely you're looking at a bigger trailer to spend more time away
from the snow!
In my mind, a Pilot would keep more options open. Prices are comparable, at least in our area, but availability of the Tribeca is very limited. I'd also be a little nervous of owning a vehicle that uncommon in terms of long-term availability of parts & service. Perhaps they are more common in Canada.
Many of these considerations would also apply to the Highlander, another popular choice for the size trailers you are considering. We cross-shopped Highlanders, but found the right deal on a Pilot first.