TCL's 8K 6-Series TVs aren't here yet, but the company has started selling the 85-inch XL Series 4K TVs that it announced earlier this year. If size matters more than picture quality, then the 4-Series TV is for you. It's massive, runs the Roku OS, is 4K and has HDR support, all for $1,600. There may be better TVs with more advanced features, but they won't get bigger or cheaper, and you can find them right now at Amazon or Best Buy.
If you don't want to make many compromises, then the 7-Series 85R745 is the one for you. It's also 85-inches measured diagonally with 4K resolution and HDR, but it adds quantum dot technology for better colors and contrast, 192 dimming zones for better control of the backlighting and TCL's AiPQ processing. It includes support for Dolby Vision HDR and Dolby Atmos audio, as well as refresh rates of up to 120 HZ with support for variable refresh rate (VRR), which is one of my favorite features for the new consoles and video cards.
All of those features add up, and the higher-end XL series, so it costs a bit more. Amazon and Best Buy both list the 85R745 as available now, with shipments starting by the end of the month for $3,000.
If you need a reason to wait beyond cost or "how will I fit this thing in my house?" then you should know TCL also plans to release an 8K 85-inch XL series TV with the new OD Zero mini-LED technology, and on a screen that size the extra resolution may be worth it. The only question is how long you'll have to wait and how much it might cost.