I've played more small and unusual set ups over the years then I can even count, including a stint with a few different cocktail set ups, percussion, etc. In the end my absolute favorite "low volume" set up is just my snare and brush, add the bass drum if you need a subtle "boom" to compliment your "baps" and "swooshes". Most of the time I would play this standing like a cocktail set. If your bass drum tom mount fits a snare stand you can throw it right there and have a single piece to haul. If you really need the toms on your set-up another one I had fun with for years was playing a 16" floor tom in the usual seated position with an inverted kick pedal on the bottom and a regular snare. Set up basically like a 3 or 4 piece kit but sans bass drum. Dixon just dropped the "little roomer" or if you are even remotely handy you can do this same thing with a cheap Craigslist floor tom and pedal.
If you really go the route of a true cocktail drum I HIGHLY suggest you look into building a baffle for the middle to help isolate your "bass drum" from your top drum. And on that note, I'm a purist in that I like the old school single drum cocktails (bass on bottom, snare fan on top) but if you want a more authoritative and traditional snare sound you will have to mount a proper snare.
The last decade or so I've gigged with a 2 piece (kick + snare), very occasionally adding a floor tom, and never more the hats + ride, usually just the ride.