What a wonderful prize! Enjoy your trip.
My first move regarding the sewing machine would be to contact the shop or retreat center. They may have ones that could be borrowed, or know where you might rent.
If that doesn't work out, and you are interested in purchasing, contact shops that are near the event. At least you'd save hauling or shipping one way.
With bag sewing being one of the activities, I would be careful about getting a machine. Some bags have a lot of layers of fabric and stabilizer to get through and not all machines can do it. A friend borrowed mine for part of a class (I think it was for the Professional Tote) bc her Pfaff wasn't balking at the thickness.
As I travel quite a bit, I bought a Featherweight specifically for that purpose. In addition, I bought a Blue Fig tote for it. I do wrap the machine in bubble wrap inside the case, which then goes in the tote, but have not had any problems. I have also shipped it via UPS 2x in this way and have not had any problems. UPS tracking is much more user friendly than USPS.
Again, congratulations and have a great trip!