You can combine them into one card at
disneygiftcard.com as long as the total isn't more than $1,000. You can't load them into any of the Disney apps so you'll need to hold onto the one card if you combine. Also you can add the information to your notes app and you might be able to use it without having the physical card. I would recommend having at least one card with a $0 balance that way if you lose a card you can transfer the remaining balance. Also I would delete your cards from
disneygiftcard.com after combining as it isn't a mobile wallet and if it gets hacked you could lose part or all of the balance of your cards.