I have that first gen 14-140. Since I bought my 45-175 last year I have not touched it, I would much rather take the 12-32 and the 45-175 with me, and have the hassle of changing lenses. It is also heavy as hell in comparison and awkward to use. It takes reasonable photos for sure, but if you want to make them special then they do need some work in PP. The 12mm end on the small lens may well serve you really well in Iceland.
It is obvious that the new generations of the 14-140 are much better, but if you're going to spend some money my advice would be to buy a 45-175 rather than the lovely lump that is the old 14-140.
As always, there's also the
two lenses are better than one aspect too - if you have a failure with one you still have another, and you'll be a long way from a camera store