There is "intonation lite" and then there is "advanced intonation" IMHO
If there isnt enough travel in the bridge saddles, then you have to start messing with bridge height and or overall saddle positioning.. (which isnt always an option on some gtrs)
If you are dealing with one of those jagged looking gtrs, one build for "metal" music you can probably do anything you want as it will usually have one of those fully adjustable bridges, but getting the more classic models like a Tele or Les Paul or strat adjusted for non standard tuning can be a b!tch... as the bridges on them can be real basic.... IMHO
It can be a case of "how low can you go"? - "err.... not too far really"
