There are several threads about Yellowstone, with video too (mine is one). I can't say enough about the trip.
We spent three days riding in the park, and one day taking the Cody to Cooke City loop, another "must do".
When we were there, we saw several Spyders on the road, and one group in our cabin area - farmers from Georgia. The group shipped their Spyders to Denver, and rode from there, returned to Denver, and had their Spyders shipped home. They were all on RSs, and were all over my RT - I suspect, from the comments, they all have RTs now.
Temperatures and altitudes change A LOT in the park. You really can have frost in the morning and bake in the afternoon, hit brief T-storms, or even brief light snow (early or late in the season) - but you can also cross the continental divide twice on the same road!! Take some basics stuff, if you stay in the Cabins - coffee, something to heat it with, and a collapsable chair (all of this takes a small space in my top case - far less than a gallon gas can. Also, either carry a full cover, or park in a covered trailer (like we did) to keep the Spyder safe & dry.
I've done Glacier, Waterton, Zion, Yosemite, Jasper, and Yellowstone on a bike, and only the Road to the Glaciers (Jasper) exceeds Yellowstone.