Bear with me on me this one it will take some stacking and it requires that you got one of the 20% off coupons from Black Friday. So YMMV but I've been waiting for a good deal to use this coupon for.
Today you can purchase $600 in Target gift cards for 10% off https://www.target.com/c/target-g...bspnbspnbs
this will require 2 transactions of $300 each on different accounts/cards since the deal caps out at $300.
Now add the TCL 65S405 to your cart online. Add your 20% off coupon from Black Friday and check out with your gift cards and your red card for the remainder of the balance. I haven't done this yet this year but in past years as long as you have your red card on your account you get 5% off the entire purchase even if only part of it is being paid for with the red card. This brings down your total out of pocket to $547.99 + tax
Good luck I'll be able to test this out starting tomorrow since the gift cards are not redeemable till 12/4
UPDATE: someone pointed out in the comments that you can no longer get 5% off your entire purchase when only a portion of it is on the red card so it looks like this deal is slightly less slick and only gets you down to 579.99 + tax still a pretty good price IMHO