We are doing this. We are FI, but was planning on DH working a couple more years to further cushion our retirement. Lately, every day at his former job has become such a dredge for him. Negative nasty people, felt like he was not making a difference, etc really bothered him. Here's the reality: DH is just not wired to not work. Lots of double negatives in there, so to say another way, DH will probably always work outside the home and I needed to accept that. I, on the other hand, would be happy to never work again.
DH just wrapped up his high stress, long hours $200k/yr job. He walked away from extra bonuses, stock options, etc. He is now doing something he LOVES but it just barely pays our bills. He loves it. He can't wait to wake up in the morning because he wants to get back at working at this new gig. He has a lighter schedule, more predictable, just a few days a week, lots of time off. He loves it. People he works with love their job too and it is such a positive environment. I can see DH doing this for years and years. He has more energy and his former job just drained him. Mo' money mo' problems, as they say.
So, for all intents and purposes, I would say we wrapped up our retirement savings goals and will just spend whatever he makes going forward. Begin our Roth conversion pipeline in 2018 and pay those extra taxes now while we still have our 2 little tax exemptions, otherwise known as kids. In a few years, we will be wealthier than we could spend. Maybe he worked too long and could have pursued the path you are thinking of sooner.
I hope this story has helped. Life is very short. It's not worth the stress to be miserable. If DH had known he would have had this much fun doing this job, I guarantee he would have cut even more stuff sooner to make this job a reality. It took him a long time to realize that spending money does not make you happy, but for him, it is doing work you truly love that makes him happy.