My pipes froze and I have thawed them out but still have no water. My question is can an expansion tank freeze?

Well water? If so, then by "expansion tank", do you mean "pressure tank"?

Maine, you should know more tomorrow. I had a very small patch of frozen pipe no more than 3-4" between the main home and an addition. I heated the house to 72 degrees and it took 15 hours for that section to thaw. Please close your main tonight before going to bed. You could have a burst pipe that won't leak until the thaw.