To answer the OP's rhetorical question - Yes.
In a few weeks I will mark my six year anniversary of entering the full time working world (following graduation from grad school in 2004). I will also turn 30 this summer. In these six years we have managed to accumulate roughly half of what it will take to FIRE, all the while reducing long term debt. We may not be quite half way there though depending on how much padding in our budgets we may feel we need ("just one more year" you know...).
With roughly half of what we need already in our portfolio, the heavy lifting is done. Much of our future net worth increase will come from market returns. The recent health insurance bill also reduced the target portfolio value significantly, hence accelerating our FIRE plans by a year or two.
I figure there is a 50% chance we will be FI in another 5 years (depending on market returns). Probably a 80-90% chance of hitting the FI number plus a little cushion in 7-8 years (age 36-37 for me). It is hard to predict the future, but I could foresee some sabbaticals, "taking time off", part time work, etc happening as we get closer to FI (ie early semi retirement).
Currently we have 2 young children ages 3 and 5. When I am 38, the eldest child will be one year shy of starting high school. We may have an inkling of what college costs will likely be like at that point. Lots of current unknowns will hopefully become clearer like higher ed cost inflation rate, potential to obtain scholarships, what universities our children may attend. Ultimately it will still be an estimate, so any decision to withdraw from the workforce probably won't be permanent or final (just in case).
As far as the Kaderli's go - I admire them a lot! I am definitely interested in trying out the lifestyle for a while, but it is hard with family, and DW couldn't part with her extended family for extended stretches (we currently live 2-3 miles from all of them). I think the idea of homeschooling my kids while globetrotting on a budget is intimidating, but exciting at the same time and could be extremely rewarding for our kids too (but require sacrifices as well). We could probably swing the perpetual traveler lifestyle right now, but our jobs pay pretty well, aren't too bad at the moment, and life is otherwise very comfortable and relatively low cost here. The oldest child starts school in the fall and current plans have us staying put for a while.