Ok if we're gonna start problem-solving, I'm up for that.
Another discussion about bringing the pup to Sister's home (calm, lead with your feelings, Sohard) is definitely in order.
Other practical thoughts:
1. Can everyone come to your place for MLK?
2. Could you skip this holiday and stay home?
3. Is it commutable? Could you drive up for a few hours for a couple of the days
4. Could you stay in a hotel?
5. How about if the pup hangs out in the car (I don't know where you are, so don't know if weather would permit that) and you visit him often? Poor option, maybe - I'm just brainstorming. Combo of 4 & 5 could work...