I went on an all inclusive boat with about the same period of sobriety as you will have.
It wasn't as hard as I thought it was going to be. I just told myself I wasn't drinking, that nothing was going to stop me from being sober. I enjoyed the holiday more than any other holiday I've had... had lots of fun and no sore heads in the morning.
My way of getting through it was heading off to bed if I was finding it difficult.