Larry,

The problem with that particular Morningstar is that it uses both ambient temp (at the controller) and had the ability for remote sensing temp. When you remove the remote it reverts to ambient temp at the controller. Ambient temp controller can be a real PITA especially when the batts are in a hot space and the controller in a cool space or vice verse...

Your best bet for winter is to turn off the EQ function then switch the profile to GEL.. If you have the computer interface you can create a custom program to keep it in float constantly. All controllers tend to re-set each night and start the next day in absorption mode unless the current used puts the panel into bulk first. For this reason when boats are left idle for long periods with solar I generally choose a lower absorption voltage.