One thing about RV parking at the main lot, they have you park at the very end of the aisles, so make sure you and everyone in your group are prepared for a bit of a hike to the tram. For this reason, we used our own tandem stroller when our kids were toddlers.
At Universal, there is a lot for RVs, buses, and semis at the far end of the parking garages. Pretty much on the other end of the garages from the walkway to the parks. Again, quite a walk to get there.
When at Universal, we had my teenage sisters with us that lasted much longer in the parks than our toddlers, so we went back to the RV until they closed the parks. Fired up the gennie, kicked on the A/C. The kids slept while my wife and I watched a movie. No one seemed to care. Not sure about Disney though. We all left the park at the same time.