Sorry to say, but no. I'm at work looking at my mug right now, and beneth the handle it says in cap letters:
REFILLABLE ONLY AT LOCATION PURCHASED. And it also says: FREE REFILLS UNTIL THE END OF YOUR STAY.
So you have to purchase a mug at each resort during your split stay. If a CM let's you get away with it, then fine. I'm just stating the policy printed on the mugs. (Got my mug Dec. 2003.)
Diznee25