not to rain on anyone's parade here, and I realise that as a renter I am one of a tiny minority on mumsnet, but if you can't sell your house, and you need to or really want to, then I think you know what you need to do, right? lower the price. it's not rocket science. if my investments have lost 30% in the last year (and they have), and the cash I have in the bank is in pounds and therefore worth a lot less than it was 6 months ago and isn't earning any interest, do you really think I'm going to pay you a peak price for your house?
and it's not like we're the only family in this situation...in fact we are better off than many, with no place we need to sell, a big deposit and one of us with a stable job. even so, there's absolutely no chance we will be buying a house for more than the 2004 price, if that. house prices are still insane, relative to incomes. we can wait, though we won't if we find something nice which is reasonably priced.
and as for someone who "can't" let out a rental property or sell it - I find it a little hard to feel sorry for them. most of us can only dream of having enough money to buy a second home to let out. if it works out for them, great, but no one guarantees buy-to-letters win every time, any more than they guarantee those who put money into stocks or any other investment. timing is everything.
that said, good luck and I hope you all do manage to sell when you need to - but a dose of realism, please!