Okay, here were was my experience from the trip.
1) Beautiful beautiful beautiful. The GC is a gift to see and behold.
2) I used the 28mm prime (60%) and 70-200 (15%) a lot more than I thought I would. The 24-70 got less use than I thought it would, perhaps the remaining 25%. I didn't buy/rent the ultrawide, and I don't think I needed it. Someone suggested to go pano on the tripod if I needed more width, and I only needed to do that 3-4 times. Great tip.
3) Don't leave right at sunset. The light immediately after sunset can ping pong off of clouds and do some great things.
4) ND grads are punishing to dial in when it's cold, windy and you are aching from leaning over a tripod setup for an extended period. They also are hard to proof for correct placement, even at a 100% pixel playback on the 5d3's screen. Such a powerful tool needs a simpler implementation and verification, IMHO. I'm sure I'll get better at using them, but that was the biggest fail of the trip for me.
5) I shot much more handheld than I thought I would. The tripod only came out about a dozen times over the two days.
6) I brought the big stopper (10 stop darkener) and didn't use it on day one when I had great fluffy clouds. Day two there wasn't a cloud in the sky. So if you have the clouds, use it when you can. :-P
7) Simultaneous ND grad + panorama is the way to madness. I'm only using ND grads on single shots until I get better at using them.
8 ) Though it's 101 photo stuff, don't use s--- filters. I have B+W MRC UVs and CPLs for everything except my staple 77mm CPL (which was a mid-grade Hoya). As it was my only 77mm CPL, I had to constantly switch it out from the 24-70 to the 70-200. It unthreads, the two rings wiggle w.r.t. to each other, etc. I was fed up with it. [I just rectified that with a 77mm Kaesemann MRC CPL purchase, btw.]
9) Though I knew this would happen, the 24 end of the 24-70 and the 28 prime both demonstrated FOV-CPL-'pseudo-vignetting' from differing levels of sky darkness. It goes away around 35mm and up from my experience. I know you folks brought it up, and I have fought that for years with my old 10-22 EF-S lens. But I did it anyway. I just felt the sky would have been too bright if I didn't accept this tradeoff, and the CPL is 100x easier to use than the (more appropriate) ND grads.
10) A monstrous bull elk walked into the GC village behind my hotel, and in nearly complete darkness, I netted a proof-of-bigfoot level of usefulness shot of him at ISO 25,600 + handheld + fully open + IS on my 70-200mm F/2.8L IS II. I saw details and colors in that shot that my naked eyes could not see. Love my 5D3.
More will hit me later, but I had a tremendous trip and learned even more about my love of photography in the process. Would do it again in a heartbeat.
Thanks again for your copious tips and insights.