I assert that by the time it's gotten to the point that you have gone out, slogged thru hundreds of job postings, had interviews, negotiated a new position, YOU'RE DONE AT YOUR OLD JOB. And there's no going back.
I could be alone here, but I never stop looking at job postings. If I ever see something more interesting than my current job, why not explore it. Chances are you would miss the most interesting opportunities if you weren't looking 90% of the time. The best time to search for jobs and interview is when you already have a comfortable job. Then your desperation doesn't force you to take something you don't love.