The final cut of the 9th episode of the Tesla Motors Club Podcast, featuring Chad Schwitters, the former president of Plug In America, is now available. You can watch it now on YouTube or listen to it on all major podcast networks.
Never tried it, but it's similar to elevation changes in CA mountains. Looks like a 3000' rise, so you would want to allow 30 more miles of travel or 150 miles of range needed. Then you want buffer of maybe 50 miles. I would guess an 85 could, would make it with no problem. Looks like the speed is OK. Here in CA, people think they need to go over the pass (6000 foot rise) at 75 mph, but luckily it's only about 40 miles and downhill on the other side.
I wouldn't go without a full battery. Or 95% on a 90D. Until you've done it and know how much it takes, take it easy.
I'm assuming, of course, there's a charger in Grand Lake.