compensation from Easyjet
if you decide to pursue compensation, and it seems likely in this case you are entitled then in my experience Easyjet will try and wiggle out of it. If the runway works was indeed the cause then Easyjet could have fixed their sales computer to stop selling tickets once the plane was 80% full or whatever the limit was.
Anyways, use the online Easyjet system to immediately lodge a claim for compo including the EU money and hotels, phone calls etc. After a month don't negotiate just say you'll be lodging a small claims court claim within 7 days. After 7 days lodge the claim costs about £60 quid and do it online takes 10 mins. At this point Easyjet wakes up and tries to settle for 50% or so. Tell them 100% or see them in court. Cheque appears for 100% a few days later.
Been there done that. It's how they do customer service, reckoning enough people fall by the wayside to make all this reputational damage worth it.
G