Our 3 dc go to private school and there is a huge variety of people there - from those who pay the bill without blinking, to those who really really struggle. We sit somewhere in the middle. Oh, and gp pay for one child.
We have a joint income of considerably less than 100k. My salary pays fees and the cleaner and any babysitting. dh does mortgage, bills, and holidays.
We run one old car, and use the bus if we have to be in different places at the same time. We all have good quality bikes and the elder ones can bike to rugby training on their own now. Our holidays consist of going to my parents in the countryside which they love, and costs nothing. We also go to France every summer - drive down and stay in mil's house. That holiday usually costs us about £400.
But our mortgage is miles lower than op's at about £1200 a month, and fees round here are about £7500 a year for primary rising to £12000 for secondary, up to £15000 for sixth form.
It is doable, and the dc do not feel that they miss out on stuff, but although we would like to move to a bigger house, that's not going to happen.
We would have been more comfortable and felt more financially secure to use state schools until secondary (they are terrible in this city) but after 2 years in the local Ofsted Outstanding primary my eldest ds was miserable, withdrawn and learning nothing, and the school was totally unwilling to help in any way.
It means that my dc will not ski until they can pay for it themselves, and their holidays will not get more glamorous and exciting. Poor them