Wondering what I should do as I would have never thought this was going to be an issue for us but of course, sht happens.

We're an early-stage, well-capitalized Chicago based startup about to launch to general public in <1 month (been developing for 9 months). My current CTO that I've known for 5 years has some major family issues to tend to and have to go back home asap but willing to help with full launch and smooth transition. Web product is almost launch-ready, having gone through many iterations. Have an awesome, super talented designer. Marketing team and execution plan is solid (we've thought about business model and tested various hypotheses for the past 6 months). All of team major/minor hiring is complete with lots of very competent people on the team (even android mobile guy on board). Only thing that we need is a new CTO! (Rails based). Wondering what would be best way to find competent new CTO and how you guys would act in my situation. Any insight would be very much appreciated.