Upload & Sell: Off
They really wanted you. If they can make it happen, they will. If not, so what?
As for getting up, it's as simple as packing up and saying something like, "well, I do have another engagement... you have all my info and what I can offer... I'm willing to entertain possibilities around what we've discussed... please contact me as soon as you can to lock the date if you can find a way to make it happen... if not, I wish you guys the best of luck with your wedding plans... please remember that another client can lock your date if they present me with a deposit and contract before you can..." It's not that big a deal. If they really want you, all they'll hear is that last part.
My worst one was a jerk that worked out every single little detail down to final price, with tax, and deliverables, and THEN demanding the RAWs when he already knew I didn't offer them. He was a weekend photo warrior that wanted to "play". He wasted an hour of my time setting it all up just to drop that bomb on me at the end. I said no and shared my reasons why and he pushed for another 10 minutes about it. In some cases, I would have given it thought and worked out something with him, but he was being a jerk with attitude (wanting them completely free; no ifs, ands or buts) and I had to pull the above to end the consult. I never heard from him and he never booked a photographer for his wedding. I felt completely sad for the bride after seeing the results on her FB page months later. The only images she has are really bad "friends" shots.
Sometimes, you just have to let the train wreck.