In reply to Ridge:
We flew Delta from LHR, Minneapolis, Salt lake city where we had an overnight stop, then drove up to Yellowstone, about 6 hours. Stocked up in SLC as there are a couple of REI stores to buy bear spray and other provisions.
We camped in the first campground coming in from the West Yellowstone entrance which was fine but there were no showers there, we had to drive about 11 miles for a shower at one of the other lodge places where they had showers.
Then had a week at Roosevelt Lodge in one of the basic cabins.
I would recommend staying in the park. I'm glad we did it that way.
An amazing place for wildlife, birds, scenery etc and you dont have to get far off the beaten track for solitude.