From my last several visits at OKW, BCV and Ft. Wilderness there have been signs stating that refillable mugs are for your current length of stay at that particular resort. So, according to that restriction, you would not be entitled get free refills on a later visit to that or another resort.
If you mean that you are staying one night at VWL and immediately moving to a room at WL then I personally think that would be fine, as you are still at the same resort, just staying in a different section.
