@Hoosier John
In order to have the auto draft, they must have access to your account. But, you can make partial or full payment at any time. I used gift cards when I paid mine in full back in December.
I had a wild assortment of gift cards - some with a few $$ and some with up to $500. I didn't combine anything. Just applied them one by one and each time the balance dropped and when a 'month' was paid, the next payment due moved to the next month. I didn't combine because it was just extra work as the DVC site worked in the same fashion by adding each card as a credit.
You can also pay dues with a credit card. If you are not set up for auto draft, I believe the whole amount has to be paid at once.
With auto draft you can make partial payments so long as you are up to date. The 3 options online are credit card, gift card and rewards card. I used gift cards and the rewards card I got for a referral.
Prior to online access, members would send payment or call to apply gift/reward cards or credit cards.