Think this depends on the pricing structure. Are you offering a free or a paid service? Is support part and parcel of this, or do you offer different levels of support?
I'm mostly curious how other people deal with it. Do people carry a laptop everywhere so they can plug in whenever something happens? Or do people just hope for the best and deal with problems only during "office hours"?
Side note to parent comment -- we do offer the same support to free and paid plans right now.