Financing arrangements for homes >$3M

Hello!

I'm looking to settle down permanently after a career where I moved house every 2-3 years for decades.

In preparation I'm also exiting my rental property side business and will be sitting on a pile of liquidity in the next 1-2 years once I'm done selling (great time to be doing it! lol).

I started feeling out the traditional banks and regional banks, and nobody wanted to touch anything above $2M or $3M depending, despite a financial situation which would allow me to buy such a house in cash. What I heard was there simply isn't such a product out there (which I suppose is possible, given how few houses in a market outside of the SF bay would be selling at this price level).

I also looked into securities based lending, through Fidelity and others, but those arrangements tended to only be 5 years max.

I heard all the stories about "special mortgage arrangements for the elite" from the politicians for years. At the risk of pointing out to everyone how un-knowledgeable I am at high end home purchase arrangements, despite having been a landlord and working in senior finance roles for decades, I've never been offered or have seen anything like that. I was wondering if anyone on this board could at least orient me in a direction I could start chasing.

I know solution #1 is "pay the difference between purchase price and $3M in cash". I can, but I'd strongly prefer not to unless it's the only way it's done in reality, and there are no "special mortgage arrangements" of legend.

I think perhaps solution #2 is "get into a private bank and let them sort it out". An option, but I tend to manage my own investments to save on fees and would prefer to keep it that way. I may be swayed, but that's my initial reaction

Anyway, appreciate any and all help in this area!