We started out this year virtuously doing the whole shebang over two days a week (except that even between two local tiny libraries, we are almost never able to get the specific titles recommended for extra reading. I just check out anything subject-related that looks age appropriate -- I can't tell you how many books on mummies I privately vetoed because of scary mummy photographs). The children really loved the activities, but they have been the first thing to go. Unless it's a project that uses stuff I already have, like modeling clay, I never remember to buy the supplies. And since we prioritize our subjects by time, science and history always come next-to-last. (Sorry, art and music. I'm doing the best I can here.) Sometimes, we don't do any extra reading on the subjects, or, as a PP said, we're several weeks behind on our extra reading.
I do have ds6 read the lists suggested for memorization in TWTM: the principal pharaohs and the first twenty Roman emporers. After the first several frustrating episodes of my correcting his pronunciation on every name, he can speed through them pretty painlessly at the beginning of each lesson. I was surprised to find that he has memorized the pharaohs already and can name most of the emporers as well, just from reading the lists twice a week.
So that's my minimum for now. I could see dropping the worksheets if I didn't have time, or the questions.
Edited because "pharaoh" is the word I always misspell, and did, twice.