You can’t use house #1 as the collateral for both the mortgage on house #1 and house #2, because the bank is smart enough to know that you don’t actually own house #1. If house #1 has appreciated significantly from the purchase price, or you have paid off a good chunk of the mortgage, you may have enough equity to take a loan (eg home equity line of credit / HELOC) on that equity to get down-payment money for a second house. That’s generally a slow process, unless you happen to own property in a market bubble.
With 25 GbE, even 10, I’d be tempted to PXE boot client systems. Maybe still have a local PCIe SSD for windows game files.
Dunno how that would actually work with Windows, but it was fun when I did it for beowulf nodes. Setting RPis to netboot is a little involved, but you can create an OSMC image and give all your TVs a consistent ‘smart’ interface. You don’t even need 10GbE to be pretty functional for the Pi, but my experience is that WiFi is not fast enough.