Can these rolls be frozen once baked?

Yes, you can freeze these dinner rolls. It will work just fine. (In fact, more and more people, to get a head start on their holiday preparations, are baking and freezing rolls and freezing them.
It's a great idea!)

Wrap the rolls tightly in cling wrap and then in freezer paper. Bring them to room temperature and heat for 10 - 15 minutes in a 325 oven right before serving (covering with foil in the last 5 minutes, if they are dark), if you want them to be warm when they go to the table - which I recommend! ;o)