Joyce, there is an old article written by Don Hollingsworth that talks about growing peonies in hot zones, just google Don Hollingsworth growing peonies in the south and it should come up. I think it's housed on the Hollingsworth Peonies website which was down for the year the last time I tried to find it. Anyway, the article was based on conversations Don had with a peony grower in zone 10 who grew and had flower many peonies that popular wisdom said would fail, claimed the trick was to cut back the foliage to trick the plants into dormancy in the fall.
As for potted peonies, they will struggle in full sun in the summer, at least until they're more established. I'd place them where they'll get the best chill in the winter and then move them if necessary to get morning sun in the spring until bloom and maybe even more shade during the summer to keep the roots from overheating.
