RTX 3070 is absolutely, definitely overkill for 1080p at 60Hz, which is what you're going to get on a TV.
The thing is, the GPU decision should be based on if you're going to move up to 1440p any time soon, or not.
Frankly, I'd more likely recommend a 2560x1080 ultra-wide, which is a 21:9 aspect ratio rather than the usual 16:9 aspect ratio. That's my personal preference, though, as I like the extra field-of-view in gaming. You could also go 3440x1440 or 3840x1600 which are both about the same 21:9 aspect ratio, but, more pixels will of course demand more GPU horsepower.
If you're going to stick with the 1080p TV for the foreseeable future, though, I cannot recommend the RTX 2060 at all. The RX 5600 XT outperforms it, consumes a little less power, and costs less.
In fact, if you have a GOOD power-supply that has two 8-pin PCIe connectors, this particular RX 5600 XT is $229.99 (after $10 instant rebate and $20 mail-in rebate), and is almost impossible to beat.
https://www.newegg.com/msi-radeon-rx-5600-xt-rx-5600-xt-gaming-mx/p/N82E16814137571
I have no idea why this particular model requires two 8-pin PCIe connectors. It's a 150W card, and a single 8-pin alone can provide 150W, not to mention the PCIe slot itself offering up to 75W more.
That said, and while it is a very good deal and hard to pass up, you might want to wait a little longer - the AMD 6000 series cards are coming out, although their higher-end cards. But there are also going to be Black Friday sales, etc. with the coming holidays. If you're not in a hurry, there could be some amazing deals coming up.