I have been caught twice by worse than expected weather in Germany while an IMCR holder in both cases the safest course of action was to climb into IMC and seek a diversion to a VFR field which was organised with little or no drama. I wasn't even asked if I had a problem, so I suspect it's not that uncommon.
Similarly in France low cloud rolled in and screwed up my planned route royally. That time I was actually VFR on top and again with ATC help found a suitable alternative plan, though they had to work at it before we finally ended with Toussus le Noble as an alternative stop to Troyes.
