Cincinnati Ohio - When is it usually safe to dewinterize?

I've un-winterized the last week of March to go camping several times here. But usually not until early April. There is always a chance of cold here in SW Ohio in the spring. If it doesn't get too far below 32 or doesn't stay there too long, you shouldn't have any problem. I usually empty the water tank and dump the holding tanks to lower the chance of those freezing up. Then if it was to get too cold you can turn on some heat inside like another poster said.