As for getting married, I don't think there's ever an exact time frame across the board. If you feel ready, go for it.
As for the cancellation, get on it. Since you're the lady here, you might be encouraged to wait until there are real marriage plans. But once those are in place, speak to your bishop. It was not even two weeks since sticking the paperwork in the mailbox for my husband to get his sealing clearance, but it can take some time to get that paperwork done, especially if the bishops are new to the process. Like Jennarator said, who knows how long it can take? Your best bet is to do what you can to get everything in motion.
When you get to heaven, do not stop and stare. Chances are there'll be others surprised to see you there.