Visa stamping with new approval

Question regarding visa stamping - I am travelling to India in the first week of December. My current visa is valid till Mar 2017 and my extension will be applied in this week in premium processing. If I fill the DS160 and schedule a visa interview based on current visa and if I get the extension approval prior to the visa interview, would I be able to get the visa stamping based on the new approval notice? Or would i need to schedule another interview? Can i reschedule my visa interview without repaying the fee?