Let's say I want to traverse 3 hexes. The difficulty of these in order is 2, 1, and 3.
I have two cards. A 5 and a 1.
Can I travel this path?
An additional question - if I have movement of one type left over, then move over another type, then wish to move over the first type again - none of that movement carries over between types, even between the same turn, right?
For movement, just resolve each card fully before moving on to the next, and you'll have no issues.