Hey Coal Miner -
I call BS on the battery disconnect. Actually, it's good to occasionally disconnect for a 1/2 hour or so at least to reset the ECU (computer) so that it will re-learn your current driving style and adjust for both performance and gas mileage.
I have an aftermarket 3rd party "piggyback" tuner box hooked up, as I also have a tunable SRI (Short Ram Intake) and custom headers/exhaust. It needed custom tuning to run correctly and get the best balance of performance/mileage.
Any time I do something new to my car, I disconnect the battery about an hour and let it reset everything to re-learn how the car is functioning. This would also be wise if you are relocating to a higher elevation for an extended period of time as well.
Just a little insight on that at least. Leaving it off for the winter is probably the best thing you can do for your car.
Cheers,
Jeff