In words of the Scottish bard "The best laid schemes o' mice an' men gang aft a-gley". The considered opinion of Margo and Chris is that they are unlikely to be in Europe by prime or even decent biking season. Their current estimate is that they would be in Turkey by October which is a prime biking time. Having done some initial research, Turkey sounds very appealing. It would also likely irritate my Greek co-irker, and thus be no bad thing. (She has a number of strong, politically incorrent opinions on a number of subjects including Turkey.)
The annoying thing about this change is that it rather precludes alternate plans in the same time-frame. Unless I am very much mistaken or particularly lucky, October is far from a good time for long distance cycle-touring in Canada or France. Thus committing to Turkey leaves relatively little room for alternate holidays. Although, as September and October aren't high season for vacations, I might have some wiggle room with management.
In any case, I still have more than to months to even begin to make a decision. Besides it is getting late-ish and I am slightly drunk. Defer, postpone, delay.