Doing it that way also leaves you without lights--a particular problem if you've decided to go all or nothing into the dynamo setup.
Before I switched to dynamo lights, I had a second set of wheels. Never needed them for that purpose. (I used them for snow vs three-season tires.) Since I switched to dynamos, I don't bother.
In 33,908 miles of cycling over the past seven years, I've had a morning flat once. This past Thursday. Since I never wait for the last minute to leave and I get the bike ready while the coffee's perking, it wasn't an emergency.
All good points to think about.
I do have the train which permits cycles as a back-up, which means that I could always get at least one ride in during the day. I really miss being on the bike after months of not commuting.
Thanks.