My two primary bikes are set up very similar to one another, which means that I can swap parts from one to the other to make things faster. If I ever had a flat, I could just swap wheels. One other thing is to prevent these sorts of mishaps. I use Schwalbe Marathon + tires, and have not had a flat in over 15,000 miles now. I do routine maintenance on the weekends and rarely have failures come up as a surprise.