We had a similar issue (though sadly not in the same part of the country as you are as your prices sound incredible!) - we saw it soon after came on market (after being on with another agent since March very overpriced), first to see it. Really wanted it. We are no chain, vendor is no chain. We are renting, 20% deposit, mortgage agreed in principle.
We saw it begning of August, put in, frankly, a p take offer (85K under asking price), then a couple more (-60K, -50K) over a period of a few weeks. Then stopped, said we really want this house, offer remains on table, as suggested here. It cooled off for a bit, another buyer came in with slightly higher offer we continued looking with the same estate agent and others. We held back but continued to assert it was the house for us. September came and went. Other buyers chain collapsed. Estate agent indicated they would sell if we went up 15K to what they had, in fairness, been consistently saying was the bare minimum vendor was willing to consider (35K off asking price). We went to that early October and they ummed and aahged. Came back after the weekend and did the old "just 5K more and she'll go for it" routine.
We said no that's it, we're stopping here as we know we are comfortable with a mortgage for this amount, anymore and we dont want to risk comiting to it and then having finance issues. Handily, we had seen another property we liked with the same agent that weekend so we put a semi-serious offer in on that (as plan B really). This worked well as I think they knew we weren't going any higher, really wanted the house but could stand to lose it. Next day they said vendor doesn't want to lose you as a good purchaser (not many out there at moment I don't think!), you can have it for the last offer of -35K which was about 6/7% off.
So in short, if our experience anything to go by, it is possible in this market, but you may have to stand your ground and hold your nerve a bit and wait (and be prepared to lose it).