They seem good tents, but I think you would be unnecessarily cold. Single walls don't offer that layer of trapped air insulation that doubles do, and the BD 'light' tents have very thin walls.
As for strength, they're probably fine, but just because something has been used in the high Himalaya/Karakoram doesn't make it good for Alaska. Weight is more of an issue in the Himalaya so you take a few more risks, and generally you're not up high in storms. Not sure how the Guiding Light would go under a big dump of snow or truly high winds. Why did BD stop making them?
I've used a Firstlight in -25C cold and dry conditions, door 1/3 open, and got bad condensation buildup, but others say they're fine. I must breathe wrong.