One thing worth considering: Evacuation costs can shoot up really quickly if you are unable to be flown commercially and/or need assistance from medical professionals during the flight. 100K might get you home trouble-free if you live in the US and are travelling in Mexico or Canada, but if you're farther away from home and develop a complication that necessitates an immediate evacuation, you can be in the 500K to 600K territory really quickly. I wouldn't go below USD 1 million in coverage and personally have a policy that pays up to USD 2 million for med evacs.
If things really go south, you could end up being saddled with a debt you won't be able to repay for the rest of your life if the coverage isn't high enough.