What is your base fitness like UB? I started 2 weeks early, and had a week in Dec off ill, and some crappy days throughout. So I had a 12 week base, 10 week build and 10 week peak. Just get some time under your belt at the beginning.
I had a crappy week somewhere in April and missed most of that week. I started the following week with the following week's plan. The plan will sway to an extent to outside pressures (family/job/real life) i,e. stuff that really matters, not IM!
Over the ~30 weeks you will miss sessions, and afterwards you will know whether you needed to miss those, of whether you just needed to HTFU. You can draw upon this for next time. An example for me - off a plane on any given Thur after a full day. I feel tired, but after missing that workout early on, I know that I just had to get out and do it.
The week in Lanza should be easy - all that training and no real life to get in the way!