Questions about keeping boat in marina all winter

I rented a slip in a Dallas area marina this summer and am wondering what I should expect over the winter. What should I do in preparation for winter? Should I keep the motor tilt down so it is in the water?

Or should I take the boat out of the slip all together?

i would take it out. my boat is in slings over the water at my house and condensation is a real problem in the fuel and storage compartments. being close to the water in the slings seems to promote the condensation. our weather here on the coast is more tropical than in Dallas, so you may not have as much problem.

One of my concerns is freezing weather. Prior to renting the slip I always kept it in my garage, but I know a lot of boats are kept in the water all year.