In the English "5 times easier than" the number 5 doesn't usually seem to refer to anything concrete or easily measurable.
Therefore I'd regard it as an idiom rather than an actual numerical comparison.
I see no difference between "flying is ten times harder than driving" and "flying is much harder than driving".
(If you do, please elaborate on what the difference it. I don't think ease or difficulty can be meaningfully boiled down to a number.)
To compare degrees of difficulty, ease, and other such things, you just need to add one the many possible adverbs to the comparatives.
For example: multo facilius or paulo melior.
Latin does not seem to have idioms with numerical comparisons.
You can also take a look at the "piece of cake" question and see if something there could be modified to work in your case.
If you want to know how to say "Livia has 5 times more money than Maria", then an actual numerical comparison is needed.
Any discussion of that should be taken to a separate question, though, as it is quite different from what you asked about here.