Um. Having been in this situation, but being now in my late 50s so sort of past the main stress point (which is young kids), permit me to assure you that the kids are NOT harmed. It's amazing what varied homes children can come from and be perfectly fine as long as there is no ongoing fighting around them.
The person who suffers is the non-workaholic parent (aka me, back then). You have to decide what you yourself are suffering and what can be mitigated.
By mitigation I mean that if the other party is that much of a workaholic they are presumably either already earning, or have a good prospect of earning soon enough that, say, a mortgage lender would take their prospects seriously (think he's founded a start-up or whatever). In which case, there should be enough money around to fund help.
One example of that is some childcare assistance. Even a full-time SAH mother needs breaks. Plus someone else to help clean the house. If it's worth his working that full-on, it must be worth the outsourcing.
But a more serious issue will be the mother's (and therefore children's) long-term financial safety. What if there's a divorce? Can you arrange a post-nup, or some other contract? Bear in mind, that if the assets and income are solid, no court will allow him to throw you totally onto public minimums.
And that's just the money. If you feel he's neglecting you, if you feel ignored and unloved, that's a whole separate problem.
Or if, for example, you feel you also want the glory and joys of success in a career (and why not?) then you may not be at all happy him hogging it all. Especially if you can't see an end in sight. But if you are just pissed off with his assuming his career matters more than yours, do stop and think about whether you really care. For example, I was very very pissed off for quite a long time at his assumption, but ultimately, I concluded for myself that I didn't actually care that much about work: I think work is something that should fund a happy family, not the other way around.
Your issue will be if you're not sure that his workaholism (or hers: apologies for the assumption about the gender split here) won't necessarily pay off for you too, emotionally or financially. But don't worry about the kids. I've seen all kinds of arrangements, and as long as the parents are happy and the situation is stable, the kids are fine. Both parents working (like mine, back in times when that was not at all usual) fine. One parent earning, one more on the job at home, but with some breaks too (mine, after I figured things out) fine. Parents fighting all the time bad for the kids and the parents. Parents divorcing without a fair financial settlement bad for the kids and the nonworking spouse -- but definitely avoidable if you see it coming.