According to Jim :
I figure that draining the gas completely will ensure no varnish/junk
build up in the fuel system, but keeping fuel + stabilizer in the tank
will prevent moisture in the fuel system/carburetor. Which is better?

We just started a small engines course, and the instructor (with 40 years
experience - latest with jet engine research at the National Research
Council) said that simply running the engine dry and storing it away
is the worst _possible_ thing you can do. Hint: all the trace gasoline
left behind varnishes up almost instantly and gunks up everything.

He hasn't quite yet detailed the best way to do it ;-)

All I know is that my stihl weed wacker seems to do just fine with
a full fuel tank over the winter. Starts second pull.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.