It's the same source file. Most of them should be able to be printed up to a 16x20 (The largest size I think PhotoPass themselves will print online). However, they are usually meant to be printed as a 5x7. (I think the ToT ones I got last trip were 8x10) They usually put the border overlay on the picture before you claim it, so while you can edit the picture, you can't do too much editing. So if you take the source file and print it in the size it's meant to be, then you should be fine. If you however want to crop out most of the other people in the vehicle and then print that as a 16x20, you might have problems.
Checked out some of the ones from the last trip, Buzz was a 3840x2560px, Space as the same res. Test Track however was only 1536x1024. Those were all the original resolutions, so check with your preferred print shop to see how big they will print them. But they are all fine for 4x6 or 5x7 needs.