Still 4 to 5 years away for me, I'm thinking I will work to the number, then as I'm getting close get my FIRE travels planned and start prepping my house to rent out. I work contracts, so I'll probably see my contract at the time through to the end then not renew, unless I'm really itchy to travel and want to give notice. If I still want to do my current plan, of Russia > Trans Mongolian > China > Tibet > Onwards in Asia, summer is a good time, and I'll need time to research and get visa/tickets arranged and would happily still work when sorting it all out.
Luckily I contract through my own company, so I've got much more flexibility in paying myself across tax years etc. And no bonuses etc that I need to time correctly. As for our state pension, I've already got £100+ per week locked in, and only need 11 years more contributions to get the £155 max...So if I work 5 more years, that will leave me 6 years to buy. (You can buy extra years here). I'll probably wait and see with them, as I might pick up a part time job etc. further down the line, and I'll have 28 years in which to get my last 6 years contributions...