ssj92
I have 1200 P3 with i9 10980XE and use it with rtx 3090 and Titan V. You will be fine. 
 
I previously had 1000 G5. I did not re-use cables. The G5 cables had a sleeve on them, but P3 cables are flat, which I liked better. 

CraptacularOne


Very much doubt it while it's good to over estimate your power draw I think you are overshooting it by quite a bit. I'm on a 12th gen platform with a higher end card all watercooled system, just as many fans and 6 total drives on my PC in various forms of NVMe and SATA SSD. All with a 1k PSU. System benches at 5.2Ghz P core and 4.1Ghz E core, the RTX 3080 Ti at 2190Mhz core, 22Ghz memory and I don't go over 1000w from the wall at peak. This translates to about 850w if we assume worst case efficiency at 85%. 
 
During my daily driver settings of 5Ghz P core, 3.9Ghz E core and roughly 2070-2100Mhz core and 20Ghz on the memory for the 3080 Ti, I see spikes of about 800w from the wall during games at most which again assuming worst case efficiency from the PSU puts the system at 680w peaks during gaming. 

CraptacularOne
Grab one of these to see what something is pulling at the wall outlet
https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU
 
Of course that's not scientific or precise as you'll still need to convert it's reading to what your PSU is delivering. For instance if that is showing 1000w that doesn't mean your PC is asking for 1000w from the PSU since the PSU is just a means to transform AC to DC and you have to factor in its efficiency in doing so to arrive at your "actual" PC wattage usage. This varies too by type of load, how much load and duration of the load. I assume usually a 85% efficiency as a worst case for a gold rated PSU and 90% for a platinum rated PSU on average. Though again this is just a "guess". Regardless though, whatever the meter reads, your PSU is actually delivering a percentage lower.
 
A shame that fantastic site like Jonyguru went under as there aren't really any in-depth PSU review sites around anymore. 

CraptacularOne
I'd guess around 800w maybe a bit more at peaks for your system. Case fans, RGB strips...etc all that crap doesn't take a lot of power to run at all, barely any actually. Your AIO also draws less than a full stand alone pump like a Laing D5 or DDC pump. All your drives are also virtually irrelevant when talking about your system in a benchmarking state since they will be idle. 
 
I also think you're misunderstanding your CPU "being" at 5.3Ghz and actually being "loaded" at 5.3Ghz. They are 2 very different states. Open up HWINFO for instance and monitor your cores. you'll probably find they do all run at around 5-5.3Ghz if you set Windows to prefer maximum performance. However if you scroll down and look at your CPU's package power draw it will be very low even at those clocks while gaming. Now if you open something like Cinebench R23 and run it you'll likely see your all core clocks drop and your CPU package power skyrocket. Games don't do that to your CPU, they never will load your CPU like that at least not in its useful lifetime. 
 
When you're running something like 3Dmark Time Spy for instance you may place a 400+w load on your GPU but your CPU even though it may be running at 5+Ghz is only consuming something like 100-140w as the game/benchmark engine just can't load and saturate the CPU cores. Then when you get to the CPU test you may see your CPU spike to 250w while it runs its benchmark but then your GPU will be doing nothing and be virtually idle. 
 
So unless you're planning on running a tile renderer for hours straight, then also loading up 3Dmark to load your GPU, then setting up a massive file transfer between all your drives, then setting up a a giant photoshop project to fill all your physical RAM, then running Prime95 blend test to stress your RAM...........You see where I'm going with this? Who does that? No one, it's just not feasible to think you're going to be running all your components at full tilt all the time. It's just not gonna be a thing.