This was an issue I dealt with extensively before switching to the Cerberus X from the NCASE M1. I have a 2080 Founders Edition, and an 8086K at 1.36V for a 5GHZ all core OC. I was using a V5 NCASE M1. Prior to the 2080FE, I was using a blower model 980ti. I ran an X52 with Noctua A12 fans.
With the 980ti in place, I added two slim Noctua fans at 40% speed. They raised my OC on my card to 1450mhz from 1300mhz. At the time, I was running the X52 as an intake.
I swapped the 980ti blower for the Founders Edition 2080. My system immediately began to overheat. The 2080FE was dumping 250 watts of heat into the case, as opposed to the 980ti blowing it out the back of the case. The case got too hot to touch, and the GPU was heavily thermally throttling even with the bottom fans set for 100%.
I then swapped my X52 fans to exhaust. This fixed the GPU and case overheating, but now the CPU was melting itself at the OC. Even stock, it was running hot.
I was able to achieve a balance by setting the X52 to intake, running bottom fans as intake, and using a 92mm exhaust fan. However, I could never get the full OCs of either my CPU or GPU, and the system was now LOUD. My CPU was stuck at 4.6ghz all core OC, and the GPU topped out at 1.85ish GHZ.
Everyone complains at how loud blower fans are, and on test benches, they can't stack up to axial fans. But in the real world, in a small case like this, my blower 980ti made my whole system MUCH quieter then the axial fan 2080FE. If you are going to run a bone stock setup, and not OC anything, then this could work. If you run a hot CPU like me, get a blower card.
How did I fix the issue? I didn't. I gave up, and bought a bigger case (Cerberus X). I could have gone with the Cerberus, but I want to use this case for the next few builds, and MATX is basically dead for now which is a shame. VRMs on ITX boards are limited, and MATX has a lot more room. I installed an X62 with Noctua 140mm fans as intakes at the bottom, and a 92mm fan behind the CPU as exhaust. I plan to put one or two more slow 120mm fans at the top. I also added 10mm foam to the thick steel side panel. My system is now at an acceptable noise level, and runs very cool. But I cheated... My system DOES run at 5GHZ Prime Stable 24-7 OC on the CPU, and 2050mhz on the GPU though.
I LOVE the NCASE M1. When I built my first one, I had the aforementioned 980ti with 6700K on a Cryorig C1, and it worked wonderfully. It's a brilliant design, and I will build in it again. The V6 will be even better, and the new side panel might help alleviate some of the issues I had. However, if you're going to build it, pay close attention to the limitations of the case.