While both the PA68 and EVO 62 are VERY nice for lots of wind, I personally think the PA74 handles it well enough and offers just the volume margin needed. I even used a 4.0 on my Kombat 79 a few days ago and that was OK to. I think it has a lot to do with getting comfortable on the board you decide to ride and get the trim right so you can trust the board.
But if you really want freerider for high wind only, the PA68 will be great. Just like its bigger siblings, it has a shape that works great in a freeride setting and no doubt it will require less determination than the PA74 in powerd up 3.3 conditions. Its fast planing too, so as long as you have reasoble power its an easy board to ride. But as you say yourself, if the wind dies, 68 liters will make for a more difficult ride home.