If you want to put your account on hold for any period of time you can go to the Organizer Dashboard >> Payments >> Cancel.
Then when you are ready to restart again you can just apply your credit card again. This cancels your account payment only, NOT your actual Volunteer Organization page.
Your Volunteer Organization's page will basically be dormant and no one will be able to make changes, but all current information will remain. You won't lose anything. People who add hours during the time the account is on hold will be placed in an approval queue to be approved when the Owner signs up a new credit card.