You won't get many grapes off of a muscadine in a pot (I never have). They don't need full blazing sun all day long to make grapes but more sun does usually mean more grapes. Muscadines get big and want to take over the world but you can keep them pruned. They are harder to relocate than blackberries and both need a lot of pruning to keep them under control. I would plant it where you want it long term and hopefully get happy with pruners.