Fuego,
Just wanted to say congratulations on your progress and good luck. I'm 29 and currently live off of investment income with a similar budget to yours. My investment income is enough to keep the house warm and keep my gas tank and belly full and to put a little aside for a rainy day. But it's not quite enough for me to do some stuff I'd like to try down the road, like flight lessons, buying an RV or a sail boat, international travel, or putting a small addition onto my house.
Like you, I (hopefully) have a long road ahead of me, which makes it a bit nerve-racking imagining every possible failure scenario that could crop up over the next ~40-70 years. But I counter that a few ways. First, I've learned a ton about home and car maintenance. I've plumbed entire houses from scratch, rewired circuits, helped replace a leaky roof, re-framed walls rotted-out from water damage, replaced windows and doors. I always do the regular maintenance on my car myself and have replaced half of a rusted out undercarriage on my old sedan and installed a tow hitch. Home repairs aren't so bad when you're just paying for materials, and most of the cost of fixing a car is labor. I cultivate hobbies that are no/low-cost or that actually save or make me money; hiking, biking, gardening, home-brewing, cooking/baking, tinkering with stuff, glass blowing, wood working, reading/writing, gaming, computer programming, boat-building. I own my home outright in a nice small town and have low property taxes ($150/month).
It's a good, full and easy life.
It also puts my mind at ease knowing that the most-likely failure scenario isn't absolute destitution, it's just coming up a bit short on my annual budget, most-likely by only a few thousand dollars. That's a pretty easy shortfall to make up for through a temp job or some kind of side hustle. And you would see it coming and have years to figure out how to deal with it. So if your plan does fail, it's not likely to be a catastrophic failure, but just something that will require some adjustments, albeit unpleasant but probably just temporary.
While my goal is to be in a position to not even have to think about trying to make any money from my labor or hobbies, I'm not quite there yet. But thankfully I am at a point where I no longer need a job to sustain myself and maintain my current lifestyle. I'm much happier figuring out how to make some money to increase my portfolio here and there from stuff I enjoy doing when I'm in the mood to do it, as opposed to waking up to an alarm clock, shaving, putting on a necktie and dealing with job-related BS whether I'm in the mood to do it or not.
One other big bonus of having a large portfolio at a young age is the power of compounding interest.
One goal of mine is to set aside an additional $100k within the next few years, forget it exists aside from occasionally re-balancing the allocation, and just letting it compound on itself. So that, when I'm in my 60's, that account by itself will be approaching $1M. I'll think of it as my just-in-case "old man money".
If I don't end up spending it on health care it'll likely just go to making my nieces and nephews very happy one day.
I'm child free though so that makes all this risk-taking a little easier on the nerves. Kudos to you and your wife for pulling early retirement off as parents.