It sounds as if you like your current position and saving for early retirement is a great idea (from a 60's dev who can't retire soon). I agree with others her

It sounds as if you like your current position and saving for early retirement is a great idea (from a 60's dev who can't retire soon). I agree with others here that technologies you fear you might miss out on could be learned through side projects. Just my $.02 and I'm sure you'll make the correct decision, whatever that is, since you are thinking it through.