In my personal experience a 2 hour 1 on 1 lesson could progress you as fast as a week long group one, so it should be a no brainer. You have two days, make the time count.
Even if you can pick up the basics fast on your own (and some of them are counterintuitive), there are many subtleties of technique. You can get away with many of the bad habits that it's easy to fall into but they will ultimately limit your riding after a certain level.
We are all atheists about most of the gods that societies have ever believed in. Some of us just go one god further.