Just have to say, love the thread "title."
Given what I will lovingly refer to as your prior indecisiveness on this matter, meet with your guide at the end of your trip and give yourself the full 7 days after your tour to make a decision. Then, even if you decide to go for it, you'll have another 10 days after that to change your mind.
(Only caveat - if you have/want a February UY, you will want to decide before 2/1 and before about 1/25 if you wanted to do magical beginnings)