I am truly blessed with manageable hair so I've never packed a hairdryer. I've never owned a straightener, either. I try to wash mine the night before traveling (even with a frequent travel schedule) and do not wash hair while I'm on the go. My hair is long and good for styling up in ponytails, buns, braids, et cetera so the longer it goes without a wash - the easier it is to style in that way. Some dry shampoo and I'm good to go. If I'm gone more than 5 days at a time, I will wash my hair in the evening on a night in a let it air dry - and my hair straight naturally so I brush it a bit when it's close to dry and it looks like it's been flat ironed.
If I had to pack a hair dryer, I would get a miniature one that automatically switches voltages. I've tried hotel hair dryers before out of necessity and they are hit or miss. But yeah, I avoid washing my hair altogether when traveling whenever possible.
Alternatively, since I do travel often, I get my hair done while traveling and make someone else do it for me. So. Yeah. Solves that entire problem of crappy hair dryers and gives me a break from the madness.