Realistically you need to consider how easy it would be for him to find another job. As I mentioned the job market is bleak, as so many companies making redundancies and cut backs. Even the local supermarkets don't seem to recruit so much now they use self checkouts.
Obviously this depends on where you live, but I know where I am it's really hard.
A lot of 'school mums' work as TAs where I work. So I guess having a child at the school gives you some knowledge of the school, plus parenting experience. I do have a background in teaching so I do have that, but a lot of colleagues have no specific qualifications.
£2200 a month really isn't a lot. As I said, our groceries are on average £600 a month. Then factor in a mortgage (even if you are on a good rate now), council tax, mobile phones, gas, electric, water rates (this is where ours are extortionate) and any subscriptions you might have (netflix, Amazon). Then you have all the one offs (which you may pay monthly) such as various insurance, mot, car servicing. Birthdays, Christmas.
Also you need to consider what savings you have. While you mention having a nice car, and have no big spends planned, what if something unexpected happened - new boiler? Car breakdown and needs major work? Will you be able to continue to save if you stop work?
Also while you say knocking coffee on the head will save, unless you both buy coffee out every day this is not where money gets eaten up..it is definitely the bigger things and life will become very miserable if you find you can't afford any treats (ask my husband, he tells me I am the coffee police after I questioned him recently on always wanting a hot drink anytime we go anywhere 😂).