Yes, pretty much what you are saying is what I have. My "ferm chamber" will also be the place where my kegs are stored/served from. Right now it only has a hand full of bottled beers in there but I intend to have a couple kegs going soon (the fermenting summer ale will be ready to keg in a week or so). That means I want/need to keep it at serving temperatures.
Yes, I'm sure this is less productive than a dedicated fermentation chamber like you have but since I only brew a half dozen times a year or so I don't see it putting much of a spike into my electric bill.