I packed a 9lb+ rifle like yours when I was in my 30's, but quickly gravitated to sub 8lb rifles for elk hunting. All my elk rigs weigh between 6.5 and 7.75 lbs with scope, sling and rounds. Anymore, the 7.75lb rifle feels heavy to me.
I still bet you'll be thinking "light is right" when you're done with your hunt. But that's part of the fun and discovery of doing it and figuring it out for yourself.
As to the Selway, I'd hunt there before I'd hunt CO. There are elk there, and you'll have a real wilderness experience with fewer people. There are bulls there to be killed. It's not loaded with elk, but they're there. Anymore, wolves are a fact of life here in the Northern Rockies. Actual hunters learn how to deal with them.
Lastly, a modern 22" 30-06 can push a 180 at 2,800 safely. Book loads are light in deference to old actions chambered for the 110 yo round. And there's nothing wrong with running your 300 Mag in the 2,950 range, though you can certainly add 100 fps to that, but you already knew that!
Best,
Brad
