I'm doing similar.
The bike does get a bit of use over the winter months, I quite like those cold but sunny days for a ride. I just try to avoid the days after a frost when the salt goes down.
I'm not altogether convinced it's as bad a problem as some people make out but for a few extra pounds I just don't think it's worth taking the risk?
At the end of this month the tank will be filled with 'quality grade' petrol, run down and then refilled with the same just in case it has to stand for a couple of months.