I would bring them home for the winter. The batteries must remain charged if in the cold or they will freeze and ruin. The genie needs to run occasionally to insure that the fuel does not gum up the carb etc.
For short term storage of the gen I would sit mine in the shower and close the fuel cap vent which keeps odor to almost nothing. I would secure the battery box to discourage theft but as everyone knows locks only deter the more honest or lazy people.
Also, I try to use stabil or something n the gen fuel to keep things flowing