I've used 1000X, 1000XM2 and 1000XM3 in my job, really liked them. Got myself some XM2s, someone say on them and I claimed the insurance on them and got XM3s, had them for ages now and still love them, the reduction in hiss on the noise cancellation from XM2 to XM3 is great so definitely get XM3 at least.
My girlfriend has had XM4s for a few months and I tried them for 10 mins, the ear cups are indeed more comfy and it has some more quality of life features (That you probably won't use in your described situation) so if you can get XM4 for around £30/$50 more than the XM3 then I say go for it, but otherwise just go for the XM3s.
So, as the zebra man said, the XM3 is prob the best deal right now, in the UK right now they are £70/$100 cheaper than the XM4s. If you were going to use them in a situation where you will say, work with them on and take them on and off to speak to people a lot then get the XM4 as they have a feature that auto stops/pauses the input when you take them off (Little sensor in the earcup), you didn't mention that, but thought I'd say just in case you might also use them for work after intially just for TV watching at night.
The real issue might be connecting them to the TV in a way that doesn't have a latency/a delay, I know internal bluetooth on TVs is notoriously shit but if you do have problems then you could still get something like this -
https://www.amazon.co.uk/s?k=bluetooth+headphone+audio+transmitter&ref=nb_sb_noss - pop one of these in the headphone port on the telly and the TV will just think physical headphones are plugged in so you won't get the issue that
@Calverz described with his CX (Cal, I tagged you because maybe that product can help you too). If you don't get the cheapest one then you won't have any latency problems and you can even get one that supports two simultaneous connections so the wife can have her headphones connected at the same time and you won't have to hear her horrible voice. You can tell her the noise cancelling is off and just nod occasionally to make it seem like you can hear her, double win!
What exact TV model do you have? It will be written on a white or grey sticker on the back of the TV, it will start with a number than represents the screen size diagonal, ie 50 if you have a 50", 65 for 65", etc. If you tell me that I'll make sure it has a headphone port, as some premium Samsung sets haven't for a while.