yes you should start everything up during the winter. (Occasionally). StaBil is only designed to last about 60 days. Thats not saying it WONT last longer, Im just saying it is only guaranteed for 60. Firing everything thing up a few times during winter gets everything charged up again.
I do like the fuel shutoff valve idea. ("maybe I should add them to a few of my real snotty customers gensets-without telling them-then charge them a couple hours labor to "fix" their gennys after they throw their tantrum that the genny wont start")? Hmmmm ---- NO! bad bad bad thought, but it would be funny to pull on those people who throw that "I paid $XXX amount on this, and I deserve everything" garbage. I hear that crap from somebody at least once a week.
OK back to reality, the fuel shutoff is a good idea not only to let it run dry, but to keep anyone else from stealing a little power from your gas tank.
I started with nothing, and still have most of it left
2001 Jayco KIWI 23B
2003 Jeep Grand Cherokee 4.7 AWD