That's great! Congrats.
Worst-case scenario analyses for new job:
- it doesn't work out (you HATE it), you can't return to the old job, you have to find another --> are your skills easily transferable? Good job market near you? Probably a non-issue, even in terms of it shifting your FIRE date drastically...
- you like it SO MUCH you continue working --> FIRE date moves back, but are you FIREing for the sake of it, or because you want freedom? You may feel differently once you have reached FI and choose to keep working, than work only in pursuit of FI. In other words, does it really matter? If, in a few years, you find you want to stay, I trust you'll be making a well-informed decision, weighing your reasons for continuing to work against your other goals (like moving abroad or staying home with kids). Adding the option maybe adds some temptation, but it doesn't mean your eyes will turn green and you won't be able to leave the job. : )
Worst-case for staying at old job:
- You're only moderately happy for the next 4 years. (Aye. 4 years isn't forever, but it's not a small amount of time.)
- You decide that you want to pad your stash and decide to tack on 2 more years at a job you feel lukewarm about, but you also have to delay moving plans for awhile, so basically money has now gotten in the way of your other goals.
Best-case for new job:
- FIRE date stays the same, you are more fulfilled/challenged, you get to keep working at a job you may actually like after moving and pad your stash, you end up opening up other options for your career (not a bad thing if you decide to continue working for awhile)
Best-case for old job:
- FIRE date stays the same and peace of mind...not sure there is much more..?
I don't think there's anything wrong with either option, but at only 31, I wouldn't be all that worried about the time aspect and would instead go with the one with added flexibility. I think day-to-day happiness and a challenge at work are great reasons to take a chance on a job, when you don't really have reason to suspect it would otherwise de-rail you.