I think I'd winterize the engines as well, never know when a noreastern might come up and knock power out. I keep my boat on a lift about a 6 hr boat ride north of you. (off subject, but we boated to VA beach this year and loved it) I'd change the oil now in everything and do the works for winterizing. I love to relax in the winter for those 4 months of not worrying about the boat. I believe my winterization spreadsheet might be in the library as well, noting the order I do everything in and what I need a raft for due to being out on a lift. I do top off with fuel and stabilize (7/8 tank is fine). If you really want to not winterize then you should go with the proper heater made for the engine room. & the plug, yes I take mine out each winter as well.
Since you have your boat right there, cockpit cover would probably be fine since you can get to the boat.
