@lovelivesherenow
We've ended up in a weird, unplanned version of your (possible!) future situation. My husband doesn't work because of ill-health, and hasn't since he was in his early thirties. I do work, but not in a hugely well-paid field (my salary is about average for the UK). We have two kids and are in our 40s. We don't come from moneyed backgrounds.
I don't think your love interest's claim to be financially independent is necessarily dubious - it's entirely conceivable that he could have been mortgage-free at 45 precisely because he is older and the economy was very different a decade or more ago. OH and I have paid off mortgages early twice (and continue to be debt free) - it was just easier then. Equally, this guy is old enough to have gone to uni with no tuition fees, so he may not have had any debt from that. Back then you could get significant returns on savings accounts, so if he had a windfall/inheritance in his twenties, even with cautious investment he could have made it grow.
There's been talk of what this lifestyle looks like. Before kids we were pretty frugal. We lived in a modest house that didn't need much done to it, didn't run a car, took few holidays (because of DH's health, not because we are tight!) and just generally aren't all that spendy. We didn't go all out on our wedding or honeymoon, have never fitted a new bathroom or kitchen if the old would function, etc. If you don't work, you have the free time to chase good deals on purchases. And we've not had to pay for childcare because DH does it now they're in school, and I worked P/T when they were small and we shared it. I wouldn't say we have nothing we spend on, but we keep an eye on it.
I would be a bit concerned, as with everyone else, that though he says he wants kids he might not have faced up to the reality of what it would be like. But perhaps he has. If he's an involved uncle, say... well, he still won't know exactly what it's like, but then many of us don't really get it till we are holding the baby! I know at least a couple of men who have embraced fatherhood in their 50s; though I don't think I'd choose that, it's clearly not universal that older men don't want to.
But I think you do just have to go with this a little longer and see where it goes. You have bought yourself some time with the frozen eggs at least.