To get the 4K on XBOX ONE X.

[Karl Boerger]

In order to get 4K on XBOX ONE X. Do you need 4K and HDR. You can just have 4K part. And down the road you can get HDR part when you upgraded your 4K TV.

 

[HeyCori]

While you do need a 4K capable TV to get 4K resolutions, not every game on the Xbox One will be upgraded to 4K. In fact, WC has a handy guide for games that support 4K or enhanced visuals.

https://www.windowscentral.com/all-xbox-one-x-enhanced-games

The same is true for HDR as well. The game has to specifically support HDR. Your TV won't automatically do it for you. However, HDR is independent of a TV's resolution. For example, Sony plans to release some 1080p TVs with HDR.

Sony is bringing HDR to its 1080p TVs, and not just PS4 owners will benefit | TechRadar

So yeah, if you really wanted to, you can probably get a 1080p TV that supports HDR. However, look forward not backward. If you're in the market to buy a new TV, go 4K. Prices for a 4K TV (at least in the US) have dropped considerably. And given how long people hold on to their TVs, you're better off future proofing yourself a little by getting a 4K TV (and HDR capable if your budget allows it).