Small towns in rural areas of the middle of the country (Appalachians to Sierra Nevada) have been no problem. Cities and suburbs are more of a problem, I am mostly looking for relatively empty parking lots, street parking seldom works and urban parking places are sized for SUVs at the largest.
After a couple of tours this past year in the East (I-95 corridor from Maine to D.C.) I would say finding parking for a 30-foot anything anywhere could be a problem. I haven't been with the RV to the urbanized West Coast, but suspect that parking would be a challenge.