I agree with the other responses here, but I don't feel like this deserves to be downvoted to death either, so I'm upvoting.
I did this, quit my job and ran my startup idea full-time, without enough funding, and I have a family and a mortgage. I loved it, and I regret it, and I don't regret it, all at the same time. I had some savings, but I've used it all. I've been going full-time for a lot longer than I thought I could, but I have to get a job again. My startup is making money but not enough to pay the founders, and it will be a while before we can go full-time again. I underestimated how long bootstrapping takes, and I've since watched other people underestimate how long bootstrapping takes.
It has been more fulfilling to go full time. I'm doing exactly what I want, and I'm responsible for my own success or failure. I have learned more than I would have by doing the side project on the side. We did run our project on the side for a couple years, and it was really frustrating. Going full time was a huge breath of fresh air, and a lot more fun than adding 20-40 hours a week on top of a 40+ hour full time job. I've also have a lot more time for my family, it just came at the cost of not having a lot of money for my family.
My main takeaway from having tried this is next time I'm going to do more preparation and have a runway in place before I quit and go full-time. Whether it's savings or VC funding or whatever, not having control over the end of the runway has been a mistake.
I am very close to making the decision to the same path you took (with family and kid of course). I know each case is different but how long did bootstrapping take for you? I already put saving aside for one year (covering insurance and mortgage plus other minimal living cost). I imagine I need earn at least $85K in a year to survive the second year and so on (based on cost of living in my area). I am also thinking about doing random consulting here and there, to supplement the income of building a product. But I know it's always a trap.
It's been a little over two years since I quit my job, and we have about 10x to go revenue-wise before we can support our families. We thought we'd easily get there in a year, and by the time it happens - if it happens - it will have been at least 3-4 times longer than our estimates. This, of course, all depends on team and circumstances and luck and savings and what your business idea is.
I had some blind spots & weaknesses I didn't know about beforehand, and an overly optimistic outlook. The other people on my team admit to the same. We wouldn't have learned those things if we hadn't quit & gone full time, and learning this stuff is super valuable. But I can see now more clearly why so many entrepreneurs say that big mistakes are inevitable and why so many people talk about businesses really taking 10 years to get off the ground, rather than 1 or 2.
I have started doing some consulting, and it's super helpful money-wise, but takes a lot of energy away from the startup idea. I find that consulting for 20 billable hours a week is roughly equivalent to working 40 hours at a full time job. With a family, that doesn't leave a ton of time to work on the startup.
When I do it again, I will look for at least 2 years of runway before I go whole hog, whether that's savings or VC funding. It's also a good idea to find your family's minimum comfortable burn rate (with wiggle room for emergencies). It might be less or more than you think.
Also it's important to have a good sense of how you get customers. I'm still working on that, but I truly had no clue when we started. It's a lot harder to get the word out than I thought, the internet is extremely noisy, attention is extremely scarce, and using the internet for advertising has changed considerably just in the last 5 years. Next time I will probably try to bootstrap to cost-neutral revenue before going full time. We quit our jobs before we were making any money, and just built the product for a while. It has been awesome in many ways, but we'd be in a better spot if we'd started selling sooner and waited until we had revenue to go full time.
I did this, quit my job and ran my startup idea full-time, without enough funding, and I have a family and a mortgage. I loved it, and I regret it, and I don't regret it, all at the same time. I had some savings, but I've used it all. I've been going full-time for a lot longer than I thought I could, but I have to get a job again. My startup is making money but not enough to pay the founders, and it will be a while before we can go full-time again. I underestimated how long bootstrapping takes, and I've since watched other people underestimate how long bootstrapping takes.
It has been more fulfilling to go full time. I'm doing exactly what I want, and I'm responsible for my own success or failure. I have learned more than I would have by doing the side project on the side. We did run our project on the side for a couple years, and it was really frustrating. Going full time was a huge breath of fresh air, and a lot more fun than adding 20-40 hours a week on top of a 40+ hour full time job. I've also have a lot more time for my family, it just came at the cost of not having a lot of money for my family.
My main takeaway from having tried this is next time I'm going to do more preparation and have a runway in place before I quit and go full-time. Whether it's savings or VC funding or whatever, not having control over the end of the runway has been a mistake.