An OPS group call in the morning will decide this one I’d say. Most likely will launch as things stand but if the situation forecast wise changes or if the FAA stand mandating restrictions there is an increased chance of cancellation. If not already actioned as a cancellation you’ll be on your way to LHR I’d say if it does get canned in the morning. Right now it’s a case of plan a diversion a long way out of that system and then I’d top up on top of that to give myself a layer of ‘being mucked about’ fuel for breathing room.