If you're only driving 5.5 hours and spend 1.5 hours charging, you're doing something very wrong.I've supercharged once, and it was just to try it out. Much more expensive than home electricity. No thanks!
If I do a big trip, I can see supercharging being useful of course, but I'd rather drive 5.5 hours with ICE and a 5 minute fill up than take 7 hours because of a couple of longer charges.