Vet Med has changed for this year. It is now a donor lot. No RV's. And no overnight parking, if I recall correctly.
About mid-August, they will sell advanced passes online for the grass lots. One pass for all grass lots, first-come, first-served. I think it was about $30.
If you send me a private message about what you want (RV, car, Friday night access, etc.), I'll give you what I know and recommend.
P.S. I may have an extra Vet Med parking pass for the UNI game.