Welcome Ash! I've never grown spuds in bags, so can't speak to that. If they are putting roots outside the bag, you may well end up with spuds outside the bag. I'd just leave them where they are at since they've already become established and moving them may set them back. Spuds are easy, and one of many vegetables that the taste of fresh out of the ground just can't be replicated at the grocery store. Happy eating.
