Not sure how you have kept up on maintenance, but at that many miles I would do the upstream O2 sensor, air filter, PCV Valve, and plugs. I replaced the plugs in my Matrix at 60,000 and the electrodes were almost gone (I drive aggressively so those "100,000 mile plugs" have never lasted me that long).
Check the battery terminals for corrosion. When they get corroded, modern cars filled with electronics will do really weird things. I had a loose ground on my Focus that would make the car not start at all, but an hour later would turn over and run. Sometimes the car would completely die on me while driving until I finally chased it down. So the condition of your grounds would be another good thing to check. Make sure all of them are tight and that no wires are fraying, pinched, or otherwise damaged. I'm not exactly sure where all of the grounds are, but usually you will have a couple on the firewall, two or three on the engine block, and one or two on the transmission case.
Intermittent problems like this could be caused by hundreds of things and over the internet, it is very difficult to properly diagnose and troubleshoot. Usually I tell everyone to start with a tune-up if they have been slacking (since most issues are just that), and then go from there.
Good luck. Keep us updated.