I can only give you my little opinion.. not sure its a good one, but.... even people on the working solution, where they have 3 packs a day plus a 400 calorie meal in the evening lose weight.
Plus the fact that some people make sure they use their add a meal weeks, I don't see how bringing forward such a week could harm.
I think all of us on this diet have it settled and decided in our heads that WE WILL lose this weight, so maybe you need to decide what's going to work best for you to stay more-or-less on the wagon long term... preparing to have a less restricted week, and be ready for it is not a failure. So hopefully rather than making you think 'Oh sod it' and stopping, you can pick up where you left off.
The diet is merely a tool, like a guideline for us. I think there might be times when all of us at some point have to deviate or adapt it to fit into our plans. Things like holidays, or weddings etc things that are events in your life you'll only have once, and not to enjoy them to the full as you are worrying and stressing over the space food packs might be a shame. This is a diet for the longterm.. almost a way of life rather than a short term fix, so you already know you are motivated... things like holidays are an experience you'll never get back, so knowing you are motivated to carry the diet on afterwards and to fit it in the best you can while away, should hopefully not stop you enjoying the evenings with friends and family.
If you are going to try to stay in ketosis I would read the warnings about alcohol though.. because it might be more tempting when away.
You will come back so proud that you maintained the diet in the day, and by sticking to the food options you put in the evenings, I think you should just relax and enjoy the time away.
You have the ultimate choice honey, but just be a little gentle on yourself if the losses for that week is lower... It all balances out in the end.