survive
The parent counted as
PWC is the one who receives CB etc. Ideally you should
each have a home of the appropriate size. However there is nothing that
says it has to be owned. If there is a
FMH and it is not too large or expensive to run it may
be that the PWC would be supported to stay there and, if there is
insufficient in the pot to buy 2 properties, the other parent would need to
rent.
The £70k you say has been spent on legal bills so far
would have provided a very substantial deposit. The £500 a month he has
committed himself to would fund a repayment mortgage of some £85k or an
interest only one of £125k (at 5% over 25 years).
Hmmm.