Lakeland Carefree Resort is very close to Tiger Stadium, (about 3 miles). There are a lot of people stay at that park especially so they are close to the ball park. It is usually full all winter long, but I do know of some people who are not returning this winter. Their site may be taken now, but I also know some people who got in there winter by just calling at the right time. So you never know. Sanlan Ranch is also a nice place and it is close as well, I have never stayed there but I have visited friends there and they like it very much. It is a lot bigger park, Carefree Resort only 238 site I believe and Sanlan is at least double that or more.
Hope this helps