The hardest I ever worked for easy - indeed worked for anybody, was when I was "on loan" to the Swiss section but still based in LTN. I worked several 90 hr months culminating in a 98.30 month in August 2000 (legal under the pertaining JAR/Swiss rules).
The interesting thing, was that the rostering was done by a small office in GVA. The people there listened to their crews and tried to accommodate their wishes. In that August I only worked 16 days - the rest was off - in blocks. It suited me just fine - others less. The point is that it is possible
a) to get a lot of work from a pilot but to give him free days too and
b) to plan people according to their wishes.
Regarding b) I realise that it is a lot easier to deal with a smaller contingent in this way but a rough series of monthly bid models should be possible even for the large firm easy now is. For instance - as many weekends off as possible - no weekends off - every thursday evening free - intense blocks on then several days off - short flight periods but more days on / less off - one week free during month etc. , according personal circumstances.
That is was the late lamented Willum would have called win-win. As they say - the time is now...