Check cables for bad grounds and poor connections. Go through the major wiring with appropriate tools (screwdrivers, nutdrivers, and wrenches) and loosen connectors then tighten back up. this will break loose corrosion and let you make new contact points. You may also find a poor connection.
As an aside, I would check the ignition switch itself. It is actually 3 main pieces: The lock cylinder, the steering wheel immobilizer assembly, and the ignition switch. I had a similar failure, but instead of being 'resettable', it failed completely. It turned out to be that the switch had come apart.
As with any advice given under these circumstances; Your Mileage May Vary. Since I'm 'not there', anything I say is a Wild Guess.
Remember, it's not just a car, it's an Adventure.
Scott