Hi Gilly,
It's Lisa, your tour guide. I have spoken to the hotel about traveller's cheques and they are able to cash small amounts if necessary. (€50-100 max) The traveller's cheques would need to be in euros however, not sterling. Ironically, it's becoming more and more difficult to use traveller's cheques!
Lesley gave excellent advice about using a credit/debit card - you only take out what you need, when you need it. Please do remember to contact your bank in advance as Lesley mentioned so that they don't put a "block" on your card.
I hope this helps a bit - looking forward to meeting everyone at Dover! Not long now...
All the best to you all, Lisa