When I had my remortgage I was going to wait until right close to the expiry to action it. As we were on a better (slightly) rate with current. Erc was unavoidable.
Well, I got too twitchy. I read clauses in it saying about if house is valued too low at time of actioning it etc. I also wondered if a last minute credit check or something would scupper it.
Obviously as time went on rates were going up. So If it did fall through I'd never get that rate again.
In end I got it Done a month early. Wasn't worth the stress waiting.
Yeah, the house price dropping is the main thing - I realise any crash is unlikely to manifest until some point next year at the earliest (as more and more people come to the end of fixes), but like you say, getting twitchy! If it was just a case of a couple of months at a higher rate we'd be going for it straight away, but we would have a couple of £k in ERC to repay as well, which makes the decision a bit more difficult