Very likely yes. The weather conditions were exactly conducive for this to happen. We went through a spell of rains during the day and then eventually freezings at night preceding the won't start episode.
Immediately prior to and during the actual refusing to start, the weather was bitterly cold and freezing. Again, it had rained consistantly for days at just barely above freezing point and almost certainly dipping into freezing temperatures at certain points. Then everything froze solid.
I anticipated problems knowing only that water could potentially have found it's way into the engine compartment and cabin and then froze.
The day it finally started, yesterday, the air temperature was about 47 degrees and it was raining. I just thought, well it's thawed, so I gave it try. This is sort of funny but I thought maybe there was a saftey sensor in the seat to be sure passenger side kids could not start the car if there was no one in the driver seat; so I bounced up and down in the seat knowing the leather was cold and taunt and could possibly prevent the sensor if present from being activated. I also adjusted the seat to further ensure this. Then I pressed the peddle to floor and released it five times and then repeated this.
The car cranked over and did not start, I waited 30 seconds, cranked it over and it sputtered and started.
Early this morning while still very cold about 10 degrees, started right up. I'm leaning towards the frozen oxygen sensor theory.