If you are desperate, the screws that hold in your bottle cages have the same threading as the cleats. I had to fix a woman's shoe during an Alley-Cat I was working. She was able to finish the event.

Years ago I talked a friend into riding clipless the first time on a 65 mile ride. He was very nervous about it and afterwards said he couldn't imagine riding flat pedals again. I almost fell over last week riding too slowly through a deep puddle with floating ice chunks. That was unpleasant.