All outdoor plants do better in the ground than in pots. Now, just go round the back of my potting shed and try and count the number of rockery plants that still sitting there in pots!!!!!
In the short term leaving them in pots untill next year (or even the year after) most will survive. If you mean to leave them in pots permanently then they will need repotting every couple of years into slightly larger pots and with fresh compost. Planting them in the rockery is the easier solution.