Well, if Freedom goes and you don't, we might truck the bikes down over two days.
If Freedom doesn't go, or if he does but we decide to ride, I figure it will take 3 days each way, and yes, our first stop would probably be Pocatello. The map looks like this: Map with overnight stops. (I'm having trouble getting this map to display in Internet Explorer, but it looks fine in Firefox.)
If Freedom doesn't go the map will be the same except substitute Missoula for Helena.
I don't plan on spending much time in Vegas. I have a cousin there that I should probably stop and see briefly. Everyone else I'd see in Vegas should be in Prescott anyway.