Good choice for 20' XLR cable?

Another vote for Mogami - can't go wrong for the price and they're damn good cables

I had the same problem- Morrow Audio wouldn't make me a XLR cable long enough and I was getting into $10,000 territory with a custom set of Cardis. Since I'm not Elon that option got downvoted.

I read the PS Audio DIY article here:  https://www.psaudio.com/blogs/copper/how-to-make-a-50-high-end-xlr-interconnect/

I have made up a number of sets of these since my first try. I cannot tell the difference between them and my $600 1M Moro Audio XLRs.  Yes, if you have a real listening room fully treated with bespoke gear and outstanding source material plus a golden ear you would be able to tell the difference between the Mogami DIY stuff and the $10K cables.

My argument is that in a home stereo setup playing in a room with kids, dogs, furniture, Christmas trees a month a year, etc. the Mogami setup in that video is indistinguishable from the multi-thousands of dollar cables. 

Townshend Audio F-1 Fractal IC's

I've been very satisfied with Benchmark Media cables. Worth checking out. $153 for a pair of XLR cables, 25 feet. I'm using their XLR interconnects and speaker cables. 

Benchmark Studio&Stage™ StarQuad XLR Cable for Analog Audio - Benchmark Media Systems

+1 Mogami

XLR cables are made for very long runs. 100' is mot a problem. Cables itself has much less effect on SQ as long as you go with a well made quality cable, like Mogami. Spending 1000s on XLR cable, IMO, is money that can be much better spent elsewhere in your system.