MKAH wait for weather or purchase for FOMO

I’m considering going to MKAH on September 12th. That will be my only chance to see HEA fireworks which I really want to see. I’m thinking I should wait until I know what the weather is like. How often do they cancel fireworks for rain? Does it have to be raining hard? I’m not sure after a day at Epcot I would want a rainy night. I’m only worried that the event will sell out. What should I do? Wait for weather or buy in case it sells out? What is the likelihood of it selling out? I’m also worried about crowds surging from pushing their vacations into the week I’m there, because of the hurricane.