We just returned from a 5 night stay at the THV. We had one car, but with 9+1 people, we had to rely on bus transportation.
The only request I made was near the SSR walking path. The first THV they had assigned to us was as far from the path as possible (7003), so they found one for us that was the closest to the path as possible. In addition, it was right next to the South bus stop. Our decision was made each morning when we walked out of the treehouse. If the bus was there, we took it, if not, we walked to the Grandstand for the bus. I was leary about changing buses at SSR, but it was ok. There was always a bus monitor stationed there so we could find out when the last bus to our park had some.
I was told by the bus driver that the internal bus comes every 12 minutes. We could see the bus stop from the dining room window, so we could see a bus come and know when the next one would be there.
We really enjoyed the THV, and were surprised how spacious it felt even with 10 of us in there. We would definitely plan on staying there again.