Preheat an outdoor grill for medium heat and lightly oil the grate.
Slice the sausage links in half lengthwise, then cut into 3-inch chunks.
Place the sausage, potatoes, and cabbage into a foil bag, or lay out on a sheet of foil to be made into a sealed pouch. Slice butter into pats and place over the mixture. Sprinkle on garlic and caraway seeds. Seal the bag or pouch to prevent leakage.
Cook on the preheated grill, flipping over halfway through cook time, until sausage is browned and potatoes and cabbage are tender, about 40 minutes.