@0FreeBird0, once you've bought a card it is yours. So you can delete the cards from your collection and then redownload them anytime you want. If you are on a subscription, you will still recieve your daily cards.
But your best option in my opinion is to get an external usb drive and move your collection to it. The instructions for this are in the help section under My drive is filling up.
Hope this helps, if you need anything more just write back.