Or - dare I say?- you might need to get your head around the concept that, with your ELDEST with still 6 years to go and with the 'above inflation' rise in fees showing no sign of abating- AND bearing in mind, when you're looking at 8-12K p.a. per child, those discounts are negligible- the local state school, where 93% of the nation's DCs (and rising) are being educated may be the way to go.
The money you save can go on extra-curricular and tutoring if you feel it's necessary.
Also bear in mind that a private school in financial difficulties is not necessarily a good place for a DC to be. There are all too many stories of parents rocking up on the first day of term and finding a padlock on the gates. By then it's far to late to get the DC into a decent local state school! There may been room at another local private school but if there IS might that also indicate 'trouble ahead'? This will only get worse. Also, if a school's 'selling point' is its academia, you may well find its standards fall to where parents, perhaps 'beguiled' by the word 'private' WILL stump up the cash.
I know for a fact a situation where a DS was told he was very borderline in passing his 'highly selective and academic' secondary entrance exam from the attached prep, back in very early September, and that the parents MIGHT like to consider their DS's future- but since then the Head himself has visited the parents to ASSURE them their DS has a place -since evidently so many others have dropped out!
That DH works in finance, too, and has seen the writing on the wall, so, FWIW, they themselves have 'sadly and regretfully' decided The Time Has Come- and are settling for a local-ish comp- with a mere 84% A-C inc Maths and English at GCSE school...