Has the home been winterized before? Can you count on draining the lowest point removing enough water everywhere to prevent freezing?
If the home had been plumbed with the idea of winter draining, gravity will be your friend, if not it can make for spring surprises. Your best bet would have been to blow the pipes out with compressed air, and drain the water heater completely from the bottom drain. There is no way I would trust the heater to keep things from freezing for many reasons, what about an extended power outage?
Depending on the location of your heater, you may still have water in the lines going to it.
A few other thoughts, were the toilets completely drained, or filled with RV antifreeze? How about any sink traps? Is the water shutoff at a place where it will not freeze. Is there a well involved?
After you get it all pulled together it is not a bad idea to make a close down check list. Can't tell you how many times over the years I have gone through a shut down and get home to start questioning myself.... did I actually open that valve etc.