I have planned my rounds around holidays before and done fine. You'll still be able to enjoy all of the non-carb foods and if you cheat you can do a correction day. You'll just end up spending more time in P3 than you would have if you cheat. For me personally, I would do the round, especially if your head is in it to get the weight off. I have even started rounds early, right after P3 and been fine. Other people might not agree with it but I stabilized fine when I only took 3 weeks off between rounds. So maybe you can consider starting your next round early and having a little extra time in P3 before the holiday.