Earlier quoted context omitted.
I would suggest getting a case that has a set of inbuilt (typically vertically-oriented) expansion card slots positioned a distance away from the regular expansion card slots, mount your graphics card there, and connect it to the motherboard with a PCI-E riser cable. It's what I did and I kicked myself for not doing it years prior. I have no experience with PCI-E 5 cables, but I've a PCI-E 4 riser cable from Athena P…
Can you link to an example case and riser cable?
The "away from motherboard expansion card slots feature" isn't particularly uncommon on cases. One case that came up with a quick look around is the Phanteks Enthoo Pro 2. [2] I've seen other case manufacturers include this feature, but couldn't be arsed to spend more than a couple of minutes looking around to find more than one example to link to.
Also, there are a few smaller companies out there that make adapters [3] that will screw into a 140mm fan mounting hole and serve as an "away from motherboard" mounting bracket. You would need to remove any grilles from the mounting hole to make use of this for a graphics card.
[0] https://www.newegg.com/athena-power-8-extension-cable-black/...
[1] https://www.newegg.com/Athena-Power/BrandStore/ID-1849
[2] https://phanteks.com/product/enthoo-pro-2-tg
[3] Really, they're usually just machined metal rectangular donuts... calling them "adapters" makes them sound fancier than they are.