My guess would be that he'll be okay, since the current slack high pressure is not going to sit over us for more than a few days. I can definitely see the ban being extended even past the current limit (7am tomorrow) but I'd be very surprised if it weren't lifted this coming week. Of course, if the volcano sets off the much larger one nearby (whose name I can't remember) then all bets are off.

I'm actually slightly surprised that this hasn't become an election issue, at least at the margins. If you're a protectionist party like UKIP or the BNP, then you could use this to back up comments about how the UK shouldn't be relying on imports. It wouldn't have to be particularly intellectually coherent to attract a few extra voters.