I think it's important that, rather than doing it all in one go, you form long-term habits, otherwise you will spend your entire annual leave doing chores that just got left while you were working.
Don't stress yourself over batch-cooking. I tried it, and with the best will in the world it was more effort than it was worth, so it got ditched. I now make 5 simple meals during the week and 2 more time-consuming ones over the weekend. I cook more than is needed, so always have leftovers, which get frozen and only ever taken out on days when cooking from scratch really isn't an option - days I work late, days I'm so tired that all I want to do is collaspe in a chair, days I really fancy lasagne but can't be arsed with the faff, days I run out of money.
Deep-cleaning always sounds good, but is soul-destroying when you work full time. Saturdays I wash clothes and hang them out, add a load or two Sundays if needed. Less than an hour tops over the weekend; I never iron either and the kids tidy their washing piles away. The kitchen gets done daily or every other day at the most, the bathroom gets done on a Sunday morning after I've showered and the toilet whenever it needs doing in between (I keep those cleaners in the bathroom). I get my kids to hoover when it's necessary - usually once a week upstairs and every 2-3 days downstairs, but we have messy pets. All other bits are on a by need basis.
Events like birthdays and Christmas are planned as I go along and shopped for the same way - if I see something they'll like, I get it, put it in the back of my cupboard out of sight, and wait. Since I have a principle of a book, something to wear, something they'll like and something practical each, it's easy to keep tabs on what I still need. Cards are being made throughout the year as it's part of my hobby, so I'm never short on those.
Important dates - visits, renewals, cancellations of free subscriptions, parents' evenings, MOT, appointments etc are all written onto a physical calendar we can all contribute to.
And that's all there is to life admin, really. Don't stress yourself, enjoy your week off and stop trying to fill it with chores you can't sustain long-term.