I'd highly recommend running or biking every evening 2 hours every day until you leave for your hunt. Work your way up to some inclines if you can. Anything will be helpful. My Montana hunt was ruined last year due to several injuries stopping my workouts. Hunting the Rockies is a young man's game in most cases. It was a key contributing factor to challenge myself when I started hunting the Rockies 20 years ago. Not so much these days. 4 years of plantar fasciitis plus a pacemaker will do that.
81 is no cake walk. You will find a lot of carcasses close to the road initially, but the elk will get pushed back in quickly. We hunted right on the NM border.
Yikes! That doesn't sound like fun at all. I've done some hiking the past couple days here in Arkansas and I've come to find that I'm a little more out of shape than I thot I was. But like you said maybe running after work the next couple weeks will help.