Given that most places use 2 hours as the reserve call-out, I'd say if you can live within a 2 hour drive, you're good. I'm just 30 minutes from the employee lot at my base (no traffic), or 1 hour in traffic.
It's a completely different job, living in base, vs commuting. I commuted hub to hub for 6 months (4 hour leg each way) and hated it. I don't know how guys do it long term.
Some guys at my base do 4 or 5 hour drives each way. At that point, commuting by air starts to look more attractive. I know plenty of guys who live right at the 2 hour line, and most of them choose to drive. Knowing that your car is waiting at the end of a trip, or never stressing about missing your commute, is priceless ...