I hadn't posted to this thread before, but I'm firmly in the 2019 camp for now.
June 1, 2019 is my estimated last day of full time work.
Single - no kids
Stache:
Based on my current expenses, for barebones, my stash is at 81X
Based on my expected barebones during FIRE, my stash is at 63X
Based on my desired fun & travel FIRE budget, my stash is at 25X
The big difference between pre-FIRE 81X and FIRE 63X is dental & ACA healthcare coverage costs
But the reduction to 25X after adding fun/travel gives me some serious room to scale back on expenses if needed and lower my WR from 4% to at low as 1.6%.
If ACA goes away, I'll have to re-think everything. By my expected FIRE date, the mid-term elections will be in the past.
I don't know if it will be an option for me, and I wouldn't approach the topic with my company until the time comes, but I hope I can stay on part time for 1 year at 3 days per week, which will allow me to retain existing dental/healthcare benefits, vacation days, and retirement plan contributions.
I would also consider working 1 or 2 days per week, despite losing the benefits just mentioned. The hourly pay rate is high enough that a single work day each week is enough to pay 75% of my FIRE barebones.
If either of those is an option, I might not do it for more than a year. I'm also considering slow travel and relocating a year or so after I FIRE when I'm able to sell my house, so I wouldn't be able to work even part time at my current employer by that point. Any relocation I might do should not make a significant impact on my budget. I'm in a LCOL area, and I wouldn't move to a HCOL area.
Aside from the ACA concerns, the only other reason I consider OMY until 2020 is because I'm running in the 70% to 80% saving rate range, and it will amount to about $90,000 net more in stash value in June 2020 due to additional savings by FIREing in 2020 vs. spending from stash by FIREing in 2019. I like my job. No cubicle - I have my own office, it's stress free, it's interesting, lots of downtime. So, OMY isn't bad from the job prospective, but the extra $90,000 isn't a necessity. So for now, I'm setting up camp as a 2019 FIRE cohort.
Edit: I'm not factoring any investment growth/gains/losses into the $90,000 figure. It's just a difference in additional funds added by FIREing in 2020 vs. funds being withdrawn by FIREing in 2019.
Barebones for me includes paying all the current bills and includes expenses that may be unusually high some years like home maintenance costs, car maintenance, etc. by taking expected longer term expenses and dividing the cost out over many months.