Combine two accounts

My father recently died and lives over seven hours away. While we work on his home to sell it I would like to essentially add his account to mine instead of just being a guest on his account so I don’t have to pay for two accounts. He s this even possible? Do I have to just delete his account and the go add his camera to my Ring? Just trying to find a way to take care of this without me having to drive back down there right now…