Lars-Erik Dahle dropped me a line noting that there is apparently no way to get Tiger's iSync (version 2.0) to sync calendars more than eight weeks in advance to a mobile phone, and he's been looking for a way around that (apparently arbitrary) limitation for a while now. And I quote -
Having temporarily gone back to my V600i this Monday (as a way to avoid undue distraction from my Blackberry for a few days when I really need to, literally, GTD) and having my calendar on an Exchange server, I've been syncing its calendar via my Windows laptop, but this kind of thing irks me a bit.
Not liking iCal that much (i.e., I loathe it and don't use it, period), I never came up against that limitation myself, and digging around yielded only this outdated hint, which has enough substance to make it plain that this was possible in the past.
I've yet to dig around in iSync 2.0's innards, but any pointers towards solving this are welcome - drop me a line or post a comment if you have any insights.