Yep, if you can't mingle in your home town, you won't mingle in a foreign town.
To throw my anecdote out there, I find that I have no trouble at all talking to people on the road and making friends but I can't do that at all when I'm at home. I have very few friends at home but when I'm out traveling I find myself opening up conversations with perfect strangers. I've made some terrific friends doing that.
Just wish I could make myself do it at home, too.
My record is three weeks on the road with no conversation deeper than ordering a meal or checking in to a hotel. And I'm not really all that introverted.
I did then use gumtree to find some folks to travel with, but still, just saying 'travel' is not really a cure-all for introversion.