So many questions from this end ...
Could you clarify in what form you're hoping to acquire these bees ? On their existing brood combs, as intact colonies, hopefully ?
Will you have any stores combs available to use, albeit empty ? If so, then syrup - as thick as you can make it - would seem to be the obvious solution (sorry about the pun). After digestion, honey leaves solid matter behind which then builds-up within the bees during their long period of confinement, whereas sugar syrup does not add to this problem to the same degree.
How many weeks are you likely to have to work with, between acquiring the bees and the weather closing in ?
What over-wintering strategy (housing, insulation etc) are you planning on using - bearing in mind the depth and duration of the Alaskan winter ?
It might be worth contacting someone like Michael Palmer for advice, as he is well used to overwintering in cold conditions for long periods - although not perhaps as extreme as your own conditions will no doubt be. Maybe there are local beekeepers who over-winter, who might pass on a few tips ?
Very best of luck with this - it sounds like a very interesting challenge ...
LJ