It kinda depends on some elements of your brewing process: how much hops you used, whether they were pellet or whole, and whether you did anything to remove hops and other trub from your wort when it went from the kettle to the fermenter.
If those factors add up to a relatively low amount of trub in the primary, then yeah, you can probably siphon down to that last inch or possibly even less.
I'd put it this way: if the liquid going through your siphon tube is cloudy, don't sweat it. If there are visible chunks of stuff, lift your racking cane or auto siphon a little higher.
Bottle conditioning: Robust Porter
Drinking: Saison Dupont clone, tripel
Coming soon: Columbus APA, Rich Red ale