Will my save data still exist if I get a Digital game.

[SonytendoAmiibo]

Only one way to find out. Download the game and try it.

Worse case is you have to start the game over, but at least you will be able to play it.

You can buy locking cases for DVD/Blueray discs so the little monsters can't get to them. And they are cheaper than buying a new game. Or buy a small lockbox to put the discs in.