Unless I cruise out of my area, I use about a 1/3 to 1/2 of my tankage. And it sits in the tank all winter. These days I don't top off in the fall. I'm changing fuel filters(10 micron Racor-2 mic. secondary) every other season and despite washing machine like mixing of the tankage, I haven't had a fuel starvation issue in over 10 years.
No fuel polisher and I've taken samples from the bottom of the tank and found very little sediment.
The only thing I do is use this additive, because it's stocked at my local hardware. Must be magic!