I don't think fuel price is an issue, when all's said and done a days cruising for less than a tenner is a cheap day out. We do by the way moor on a marina and take the boat out whenever we can get up there, usually at least twice a month, and we are out most of the summer, either weekending it or on longer holidays
There a lots of boats around us that hardly ever move, but we look on it that it's what boats are for.
We are also lucky on having a long flat pound that allows for a days cruising to a number of good pubs without having to work locks which means we don't get caught up with many stoppages in the winter