It depends on where you want to eat and when you want to eat.
While character meals book up fast, as others have noted Le Cellier (especially lunch) and 'Ohana dinner are 180 day MUSTS if you want them. Things like Cali Grill timed with Wishes, Narcoosee's timed with Wishes, and Rose & Crown timed with Illuminations can book up super fast as well.
There are some other factors that come into play...
- if
free dining is offered...things will book up fast
- if you're in a park that is offering evening EMH and you want to eat in there, it's going to be a lot harder b/c of the increased crowd levels
- the adrs timed so people can get out for evening parades, shows and fireworks are also snapped up pretty quickly
- best bangs for the buck on
DDP like Tutto Italia book up quickly
- while I've had better luck the last couple of trips, when we went in 2010- all of the Fantasmic pkgs were gone for our date in a couple of days...this was also back when it was only being show twice a week or so
- some novelty dining or dining with an interesting atmosphere will also go more quickly...Coral Reef, 50s, Sci FI and Teppan Edo are coming to mind
- places that are just rumored to be good can also be harder to get...Via Napoli and Boma are coming to mind
Still, even if all of these factors are in play...there are places you will be able to eat a TS meal if you're flexible. Just in the MK area alone...places like the Wave, Kona, and GF Cafe are usually fairly easy to get a walk up for a meal. There are examples like this all over WDW.
Also, things tend to open up as you get closer to your travel dates... especially when CC guars are involved. So, if you find something you want but it's all booked- if you're willing to stalk the website daily many times per day- it's likely you'll get a spot.
All in all- I don't think you need to limit yourself to CS meals. And if possible, if you have a potential travel date...you can even try booking some ADRs around day 180 if you have any hard to get spots in mind.
