everybody gave them the road, and took their ribald insolences meekly, without venturing to talk back
Gave them the road is not an expression that native speakers of my part of the U.S. would say, so it seems outdated. As a speaker of 20th-21st century English I would interpret it to mean something like
everybody yielded them the right of way
which means, everybody got out of their way and let them pass by or whatever.
There is idiom in Cassell's Dictionary of Slang give someone the road meaning to avoid, to ignore and another entry for the same ohrase that is an alternate version of give someone the bag. When you look at that one (p. 603), none of the definitions really fit. The date given for the first entry (avoid, ignore) is 1910s+, which is weird, since Twain published P&P about 1880.
I am not sure how well ignore or avoid fits here, since the passengers also took their ribald insolences meekly, without venturing to talk back. Maybe one of the things they did was to avoid or ignore them. This definition seems to fit, and again the phrase give someone the road is not used today in my experience. But avoid can have a meaning of yield someone the right of way.
Whatever it means, it means to try to stay out of their way. Sometimes native speakers have to guess too.
Best Answer
With a phrase like "More than once", it's the nuance that is important, not the actual number. It's meant to be a contrast with "Only once". You use this phrase to emphasize that you have done something more than one time, but want to be ambiguous about exactly how many times.
This is why, in your example, it can be funny when properly phrased:
The evidence suggests that they had sex "more than once", but the joke is the implication they had sex only the three times required for procreation. Since the number is ambiguous, the listener has to "get" the inference.
Again, as with many ambiguous number-related phrases in English, the actual number doesn't matter. Possibly you want to imply something, like it is larger number than it actually is:
Or, possibly, it's been a lot of times and you want to downplay the actual number.