Well, again, as I said, it varies a lot from one FF program to the next.

Me, with AAdvatnage as my primary FF program, and using www.expertflyer.com (which shows "hidden" classes like the ones used for upgrades and awards only), I don't tend to have much problems finding international flights for leisure travel with upgrades available 3 or 4 months out, as long as I'm also flexible with exact travel dates and/or routings. I've never had to do 11 months in this program, but I hear some other programs that are a lot worse with availability some people seem to think you need it (tho that's just anectodal not scientific evaluation; InsideFlyer magazine did some tests and found that 3ish months was a sweet spot for many FF programs, tho being a US-based magazine they tested US-based FF programs more than others).

So (relative to my experience) by "plan ahead" I meant a few months, not a year or two.

Futhermore, by being an elite-status member of AA's FF program* I also always get access to exit row seats (the next best things to an upgrade) if those are left. I don't usually need to be booking more than a few WEEKS ahead to find those.

*Now that's where "loyalty" comes in: Since pretty much all my flying is leisure, I can't make elite status with any airline unless I steer most of flying, to it and its parners. (Until I get to 1MM, that is, at which point I'll be lifetime AAdvatage Gold. Given that AA is unique in that they give you lifetime status on ALL miles -- flying, bonus, hotels, rental cars, credit cards, pudding, etc -- I consider it an "investment" to try to steer as many miles into AA as I can until I get those lifetime statuses, and then I won't have to worry about steering there each year. Because of the different -- if any -- lifetime status qualification structure of all other airlines, I wouldn't be thinking this way if I wasn't using AA, because I don't fly enough to every likely get to 1 million miles based on flying alone with any other FF program. So this is just ANOTHER example of how you have to really know the ins and outs of each FF program to choose a good one for you, and then keep up with those ins and outs of the one[s] you chose to make best use of them.)