Yeah but here's the thing...you can still bone like a mofo tonight -- WITHOUT HAVING TO GIVE HER HALF YOUR SHIT WITHIN THE NEXT 2.7 years.
Listen to me R2...
It's still not too late. In fact, until you say those two magic words (actually until the official says all that "I now pronounce you blah blah blah crap) you're still in good shape. Don't blow this opportunity at LIFELONG happiness.
Will it hurt your fiancé to be jilted at the altar? Sure. Maybe. Lemme ask you this though -- what if, what IF, deep down inside SHE'S having second thoughts? What if subconsciously she really doesn't want to do this, but she's going to anyway because she thinks it'll break your heart? Have you ever asked yourself that?
Dammit R2, as a fellow tripod (well, actually, I'm more like a bipod with a tiny kickstand, but, genetically speaking my XY chromosomal makeup says I'm a tripod, but I digress...), I IMPLORE you to not go through with this. You WILL thank me later.
It might not be later today, it might not be tomorrow, but, trust me, at some point in the next 3.4 years you'll thank me when you still have ALL of your money and have moved on to banging another young hot thing.
Remember: Wives get old, but girlfriends stay young forever.