Wow. That's very powerful for F-1 students starting start-ups. The OPT is very flexible, and you don't have to pay yourself a lot of money during that timeframe unlike an H-1B. Precisely what you need to do when you start up (assuming you've at least reasonable savings to sustain yourself.)
Can you work on a startup on your own during OPT? What do you do after, if you can do the startup during OPT?
29 months is a long time to start something and launch. I think finding a local co-founder would always be helpful!