I would say that april or may would be good, even though, IME, spring and late spring can offer some very poor VFR weather, and even for IFR it often offers some huge amounts of moisture supply (read: cloud thickness) and some really low freezing levels, often down to something like 4000 feet, which happens to be more or less the IFR minimum altitude in many parts of central and northern Europe...(not true for UK, of course).
Remember that "bank holiday" is predominantly a UK term and may not be familiar to some. However, I would not think it's strictly necessary to do it on a "long" weekend. A one-day saturday come-together (with the option to stay a night) would be sufficient, wouldn't it?
Yes it would. Still, depending on distance (an important factor, especially to one who cruises at 80 knots!) and weather, for a Saturday meeting I might well take a day off on Friday, and perhaps even warn the boss not to count on my presence on Monday.
