Well, some people start off with a pot suitable for a long haul, because they don't want to disturb the roots, but I do repot every year while they are dormant if they need it, before they leaf out and they don't seem to notice. I have fooled a lot of plants that way, even Peonies and you know they do not like to be moved.
I have also added annuals to the pots to make them colorful and attractive.
I have hosta's that get four or five feet wide and they are only in three gallon pots, that should last for a while depending on how fast they grow. Some will get large quickly and others grow real slow and could take five years or more to get to a mature size. I would suggest looking up the hosta's you have on the database or if they are not there try to Google it. Get as much information as you can about each Hosta and then you can decide what size pot and where they need to go. Some need a little sun and some don't.
Can you tell us what kind of hosta's you have bought?
