As far as I understand it - Article 50 WILL be triggered, nicky (maybe someone can correct me if I'm wrong).
Cameron may be trying to put it off and pull an ace out of the hat but it seems unlikely that that is possible.
I think that if this is not your forever house, even so you need to think in terms of staying there much longer than 5 - 6 years. Will you be able to live with that comfortably? If not, then don't do it. If you will, then go ahead.
Very blunt question: does your DH make good financial decisions? Do you trust him in that aspect? if you do, if he has a good track record, then I'd be inclined to trust him. If he's made doubtful / poor decisions in the past, then stick your heels in. Other reasonable houses -will- come up in time and perhaps cheaper in the circumstances. if you plan to move on in a while, they will be a better bet. If you plan to stay in your forever house, then it's worth investing because the potential loss doesn't actually matter so much, as long as you can afford it in the first place.
About your passport and permission to remain, nothing will change for 2 years as I understand it. After that, if you've got a good job I expect somehow you'll be able to stay but perhaps not on such good terms. Maybe with a visa.