If you can't winterize your system properly and the
temperatures are going to be below freezing for a night here are a couple options to try to avoid freeze damage:
The easiest quick fix is to take an old heavy sleeping bag or blanket and cover up your vacuum breaker (the exposed part of your sprinkler at the side of your house), and as an extra precaution turn off the water source for your sprinkler (in your basement). That way, if the pipe outside does freeze and break, at least it won't be spraying water.
Remember -- these tricks will not get you through the winter safely -- your system needs to be properly drained to prevent damage, but they will carry you through an occasional cold night.
Good luck!