How do I hide one share button for a while without deleting it?

Set it to Hidden instead of deleting it:

1. Go to Marketing → Social Sharing.
2. Click Edit on the button.
3. Change Status to Hidden and click Update.

The button disappears from your product pages but keeps its Name, Icon Class and Share URL. To bring it back, edit it again and set Status to Active. Delete removes it completely, and you would have to add it again.