While I understand and agree with your identification of the attendance problem, I don't think moving the season brings a solution. Talking about the fringe kids, they are going to seek out a distraction or outside activity as the weather improves. Hell, I try to get my team outside as much as possible early and late in the season to get some Vitamin D and fresh air because the room gets monotonous very quickly. That said, how do you retain the kids?
A previous poster mentioned creating a family atmosphere, and I totally agree. As much as possible, make the room a haven for the kids to be safe and have fun while learning to be violent. Have clear expectations, but don't make threats or demands on them. Most sports have punishment for being late to or missing practice; personally my philosophy is that the punishment for missing wrestling practice is that you missed practice. You missed a chance to improve and get stronger, and someone else is taking that opportunity and will kick your butt when they face you.
It's not, at least in my mind, a need to move the season on the calendar; what is needed is an inclusive atmosphere that welcomes everyone and is grateful that they are there. Wrestling can be scary enough if you don't understand it, as coaches we're all aware of the negative publicity we get. So promote the positive benefits of the sport and you'll get more fringe kids in. You might lose some, but you'll have far more than when you started previously.