We were there right before the MNSSHP and they were selling them in a pumpkin cup. Of course it was extra. I am not sure if it is only available during MNSSHP or not.
When I purchased a Dole Whip float during the first week of October, there was a pumpkin cup sitting on the cash register with a note stating that during MNSSHP, you could purchase your dole whip in the pumpkin cup for an extra charge.