Official information from the Civil Aviation Authority:
https://www.caa.co.uk/passengers/resolving-travel-problems/delays-and-cancellations/
>>> Can I claim against easyJet for the loss of any nights accommodation I have already paid for should I not be able to get to the destination / pre-booked accommodation
No. Just as a railway company doesn't have to pay you anything if, through the late-running or cancellation of a train, you miss the concert that you'd paid mega-bucks to attend, the Ts & Cs of airline travel excludes 'consequential losses' when things go wrong.
>>> Can I claim against easyJet for additional flights / methods of travel to my destination should they cancel flights at such short notice.
Does it depend on how much notice they give of cancellation.
See the end bit of the 'Cancellations' section from my CAA link above.