Question Upgrade graphics card or go for a new PC?

[DefGun]

My System:
Case: NZXT 200i (mini-ITX)
Mainboard: Asus Rog Strix Z370-i Gaming Wifi
CPU: i7-8700k with Kraken x52 AiO
Ram: 2x Corsair Vengeance DDR4-2666MHz 8GB
Graphics card: Gigabyte GeForce RTX 2080 Gaming OC white
PSU: Corsair SF 600

I made a mistake 4 years ago when I got my parts since the graphics card almost touches the metal panel underneath of the case. I thought it was fine at that time since the panel has holes in it, the fans of the card could spin freely and under the panel is a small SFX PSU which allowed some airflow. The wear must have been substantial though since the card is overheating now and needs to be undervolted. Tried to watercool with an AiO and passiv heatsinks on VRAM and MOFSETS but those are overheating now and I get BSD after about an hour of gaming.
Now I want to upgrade my graphics card but I am limited because of the space. The card could only be about 26cm long and 4cm thick with a height maximum of 16.5cm. The most powerful card that would fit is the Gigabyte GeForce RTX 3080 Turbo 10GB, which is a blower and I‘m hesitant because it can get very loud from what I read.
The other way is to go with a custom watercooled GPU like an RTX 3090 by Gigabyte, their custom watercooled 4080 might also fight very narrowly. But then I probably need to get a new mainboard and CPU since EKWB doesn‘t support my mainboard with a CPU block (haven‘t found out why exactly). They produced a monoblock, which I might still get somewhere, but it doesn‘t cool the inductor coils of the mainboard, so I don‘t know how wise that is. I‘m hesitant about getting a new mainboard and CPU (and RAM for that matter) since my CPU usually is never under full load while gaming at 2K, which apart from coding, is the only thing that I really need the PC for.
The other option is to just ditch the case and go for whatever I like and don‘t deal with cramped space anymore.
Or am I just too focused on getting a too powerful card in since I‘m gaming at 2k? I just don‘t want to invest in a graphics card that I need to upgrade in a couple of years. I like my parts to last me as long as it works, which is also why I‘m hesitant to go for a new PC.
Obviously in any case I need to get a new PSU.
What would you do in my situation?

 

[logainofhades]

Honestly, I would probably consider a new rig, with something like a 13600k, or if near a Microcenter, maybe an R7 7700x. The later will give you more upgrade options, down the line. You could either sell the current rig, or use it as a spare rig.

 

[SkyNetRising]

The other option is to just ditch the case and go for whatever I like and don‘t deal with cramped space anymore.
What would you do in my situation?

Yeah. Get a bigger/better pc case - with mesh front and decent air flow.

 

[serafin152]

I mean if the problem is not big enough case then get a bigger one, save money and if you want buy new gpu? The one you want and not the one your case lets you.
Your specs arent that bad imo to just replace them.

 

[lordmogul]

Getting a new (bigger, with more airflow, design, mounting points for drives and fans) case will be beneficial no matter what you do. And a good case will still be cheaper than any graphics card worth upgrading when coming from a 2080. Especially if you're happy with the performance your current parts give you.

 

[DefGun]

Thank you guys, that actually makes the most sense. I did just order one now (NZXT H7 Flow) and then it occurred to me what if it‘s not the graphics card causing the BSD but the heat of the graphics card overheating the M2 SSD right next to it. I installed the SSD at the back of the motherboard and have been running heaven benchmark for hours now. The metal cover of the SSD slot is so hot you immediately remove the finger when touching it. The GPU runs at 74 degrees Celsius (165 Fahrenheit), which means the VRAM and MOFSET are much hotter right? The backplate of the graphics card is so hot that you remove a finger after touching it for a full second. Is that too hot? If yes I will still go for the bigger case and install the original cooler of the graphics card.