Wine Cooler

[Innkeeper]

OK, you're talking about a temperature control unit, not taking wine to the beach. You can keep all your wines at 55 degrees, but I would recommend 60 or 65 degrees. If you keep them at 55, you would have to let the reds warm up for awhile before serving.
As far as how long to keep them, only slightly longer than you did before. Most white wine starts to go after two or three years. Light reds don't last much longer. Medium to full bodied reds last much longer, and, indeed some must be aged before drinking. You have to make individual decisions on each bottle. The knowledge to do this comes from experiance and learning as much as you can about each wine you are storing.