welcome to GoY. I don't know where in the world you are but if in the northern hemisphere then they are pretty well established in their pots so transplanting them shouldn't be a problem. The stems will be quite tough so slugs shouldn't be a problem either.
Are these annual plants? If so I think rather than disturbing the roots in the last few months of their lives I'd plant them in their pot so they get ground water. Then when they die back just lift the pot out save the seed heads for the birds etc.

If they are one of the perennial species then yes remove them from their pots and plant into a prepared hole half as big again as the pot they are coming out of. water well.