Disabled facilities grant limits: any experiences?

[Melfish]

DF has been assessed by his OT and referred on to our local council for consideration for a Disabled Facilities Grant to sort out the downstairs for a loo and a shower. They have sent him and DM a form to complete, detailing their financial affairs.
I have PoA for DF, although only on a property and financial affairs basis. Like many parents, mine have rather convoluted finances and it will not be easy to sort out the answers to the forms within a month, which is the council deadline.
DM has rung the council to see if there are any upper limits, i.e. if you have more than £10k saved then you will not qualify for a grant, but they were rather vague. DM does not seem to want to complete the form, I assume as she has also been asked to declare her £.
I was wondering if anyone had any ideas of the upper limit regarding this grant, possibly from experience? The gov.uk website indicates that a sliding scale operates after £6k savings are recorded.