Spend good money. Order the top 5 boots on your radar all at once. Compare them in your home side by side and return all but the best fitting set. Watch for heel lift. Any more than 1/8" is bad juju. Keep in mind that any MINOR irritant while you're in your house will cause blisters while you're in AK. As you know, soooo much of this is dependent on your feet and your preference.
A few more things:
- I wouldn't buy an insulated boot
- SOCKS! All I wear is Darntough. Don't underestimate the importance of good socks.
- Silk sock liners. Have at least one pair with you. Put them on at the VERY FIRST sign of irritation
- Moleskin, BandAid HydroSeal Blister Patches, and Leukotape are your friend
- Capitalize on every opportunity to take your boots off and let your feet dry. If you're glassing and frostbite isn't a concern, take your boots off.
- Footbeds can be worth their weight in gold. Take a look at the Lathrop & Sons High Country Synergy footbed.
- If you must, go a half size big rather than a half size small. Your feet will swell.
Good brands in no particular order?
- Lowa
- Scarpa
- Lathrop & Sons
- Zamberlan
- Crispi
- Kenetrek
- Hanwag
- There are others I'm failing to mention
If you're hunting off the haul road, you shouldn't be gaining as much vertical as, say, a sheep hunter, but you will probably do your fair share of walking in muskeg. If you have weak ankles, get something stiffer with solid ankle support. If you have huge ankles that never roll and never give you any trouble, you might be well served by a softer boot. A Scarpa Charmoz, for instance is pretty stiff, but a great boot. A Kenetrek or a Lathrop is going to be somewhere in the middle. I'd avoid anything softer than that, if it were me, especially because you plan to carry a caribou.
Good luck, and buy a wolf tag.