Do you already have kids, and if so when will they be in collage? DW and I aren't planning to have ours until we are very close to being FIRE, so odd jobs and growth in the stach will cover collage expenses. That being said, I will expect them to work and save money for college themselves. As a side benefit, if you are retired and not earning money when they go into college, they might get some decent financial aid. Also, doing your first two years at community college drops the cost dramatically. I think I only payed for my books the two years I went to my local community college. As a side benefit, it was my experience that the teachers at my community college were much better at teaching then those at the sate university.
For any cost post fire, you can plan for it by just adjusting your number. If you anticipate 20K in medical a year, then use the 4% rule and bump your FIRE number up by $500k. That being said, If your consistently paying 20K a year out of pocket, you might want to look at other insurance options.
