It does depend on the boat and on the sailor. Small craft advisories do usually apply to those less than 60 feet, however you have to know your boat and what you can do. You also have to think about what you will be doing once you get offshore. And why you would be going offshore in heavy weather.
Heavy weather is what your boat can take and what you can stand. I did deliveries of new hulls for many years. The idea of only stepping up into the liferaft makes sense. I have been in a 31 footer that made it thru a cell with over 40 foot waves. And I have been in a 45 footer that made it thru 40 foot waves with much less control and more work (for days and days). And a 40 footer with at least 50 foot swells. Depends on you, depends on your crew, depends on your boat.
The important thing is, if you have any question, stay home. Once you get 200 miles offshore, you have no say in the matter. Or, my favorite thought, "What are we gonna do, pull over for the night?". If you don''t have to be out in it, why do it? Don''t risk the life of yourself and the crew. On the other hand, sometimes the hurricane takes a wild turn, or you get hit by a cell, or you wake up to find yourself surrounded by waterspouts. Unless you have a need to be somewhere, don''t go there. And, needless to say, always file a float plan if going coastal. Noone knows where to look unless they know where you should be!! So important.
If you are thinking about venturing out, invest in an EPIRB. They make ones now that have a GPS receiver/sender in them. They even have VHFs that can send your position should you have to send a mayday. Actually, all vhfs are to have a DSC system in them, but if you have no GPS unit attached, it takes a lot longer because not all the Coast Guard bases have the capability yet.
Good luck and fair winds,