Apologies in advance for the length - I will attempt to give enough information without being too outing so hopefully it will actually make sense...
Basically, I've been at my current job a long time (15+ years). For various reasons, I think it's time to move on. It's partly because of the strategic direction the company is moving in, partly that my specialist skills are not really as relevant any more and partly that I'm just fed up and bored of it. I have a three month notice period (standard in my industry).
I have been applying for other jobs that are in the same field but slightly different types of job. There is one that I really really want. I have a final interview in a couple of weeks (delayed due to holidays) and the timeline they're working to is any offer by mid/late August. I have had a number of very positive conversations about it but nothing in writing. I don't believe there are any other candidates (but I may be wrong). I also have a couple of other things that I'm in the process for which would be okay/potentially interesting but not sure it would be significantly different to what I do now.
So, if I wait to get a job before I hand in my notice, I won't be in a position to start until Nov/Dec. Which seems like a long time. I also have very little enthusiasm for my current job and the idea of having to put in a fair amount of effort for the next few months is not appealing (it's generally long hours, stressful client-facing work but I also can't afford to piss people off because I want to stay working in the same subject area). The idea of being able to wind down over the next few months is very appealing though. We're also just about to enter the strategy setting / objective setting phase of the year and I have zero interest in wasting my time on that.
But if I hand in my notice now, I feel like there's every chance that I won't get the job I really really want. My skills are in demand generally (just not in my company) so I wouldn't be massively worried about getting another job if I had to but it wouldn't be ideal and I may regret leaving my current role. But I think that's also partly because I've been in the same job for such a long time that it's familiar and I've become institutionalised.
For context, I only work 4 days a week and am studying for a masters in my spare time. I have a two year old. Financially, DH is the higher earner and we also have savings that I could dip into if needed so money is not so much of a consideration in this discussion. I have my final exams for my masters in October so part of my also thinks it wouldn't be a bad thing to have some time off to study as well.
Any wise words or anyone been in a similar position?