To be honest, you should be a little concerned. My garage is "unheated." I don't find condensation to be much of a problem during the winter until I introduce heat. I had been using a propane fired, fan forced heater when I went out to work on the bike. It heated the garage quickly, but also introduced a good deal of condensation. I've since rewired the garage to use fan forced, elec. heat but only when I plan to work on it on more moderate winter days. You can offset any condensation by wiping bare metal parts with WD-40.
The only other time(s) condensation is a problem is during fall/spring when it has been quite cold and we get one of those sudden warm days. If I open the garage, I can see the moisture collect on the bike, tools, etc.