I dont see any reason why you couldn't just use a house differently. Sure, the guild house is perfectly outfitted to be used by a guild. But if you fit some additional walls and change furniture, nothing stops you from living inside with your family.
But yea, if you still want to use it as a guild house, you can gift it to someone or build it in Exposition whereever you want to use it. you might even sell or rent it to others.