This is more out of curiosity as I'm in maintenance myself. How much of a range are you maintaining at?
I started at 18st 11. After a few targets I settled on a final target of 10st, I reverse dieted for a couple of months and dropped a little more. I've been maintaining for 4 months at 9/9½st ish. 9½ is the absolute tolerance, so I'd be back on diet calories if I hit above that.
My weight can vary a lot, I weigh in the morning before food and Friday to Saturday I was 4lb heavier (this was in the morning again, I don't mean weighing yourself right at the end of the day when you've got the weight of the day's food/drink inside you are and are 3-4lb heavier from that alone!). Obviously, nobody is gaining 4lb of fat in 24hrs so I've taken to weighing each day and then at the end of the month I take an average and compare it to the month before.
I'm currently on 2.5mg with a view to coming off in a couple of months.