Moving to Seattle from Denver - will make it into an RV family trip, suggestions?

[Lifemagician]

1) Day 1 driving the Beartooth Highway (highly recommended), and seeing the NE area of Yellowstone such as the Lamar Valley, Norris Geyser Basin,

As your route stands at the moment, this suggestion from Donna is not going to work. You will be coming into Yellowstone from the Tetons. However, you could choose to leave via the Beartooth Highway over Beartooth Pass on to Red Lodge, and your route further north.

Lifey

[Southwest Dave]

1) Where do you suggest we stop for the night between Denver & Tetons?

If you are picking up your RV same day then you shouldn't expect to get too far on day 1, especially if you are not familiar with driving such a large vehicle. Getting the paperwork and orientation done on collection can be time consuming and depending on pick up time, it could be near Noon before you get on the road. Having said that, if you were to contact the local rental office you might be able to arrange an earlier pick up time with them. [We done so with Cruise America] Somewhere around Rawlins should be comfortable but you could possibly get to Rock Springs or Landers depending on the route you take. Near Landers I see there is Sinks canyon State park which looks pretty cool but has limited RV spaces. Another option would be is take a short trip to Estes Park and explore the Bear Lake area of Rocky mountain NP and the next day head for the Tetons. That would give you time to sight see in the Tetons next day and camp in Yellowstone that night. Remember that you when you first pick up the RV you will have to stop and stock up the cupboards and get your gear stowed and beds organised and made up for the night. The other thing is that booking RV sites in National parks is essential and should be done at the earliest possible time as they fill up fast.

You say 7-10 days for the trip, well if you can mage 10 days it's gonna be a whole lot more fun and will determine how much you can do, including the Beartooth. Those 3 days will make a big difference if you can. [?]