A 50 to 55-inch TV may be more suitable for a room with a viewing distance of 8 to 10 feet.

Sorry but this space with all the windows is not ideal for TV You will need for sure solar shades and probably drapes to make viewing possible and as for the size of the TV what size do you like this is going to be really a media room . The TV always dominates a room so if this space is really just for the TV go big.

I have a relatively new 55" TV which I use as both a TV and a computer monitor. As the monitor, I usually sit about 3' from the screen, which I really like because there is much more high-definition detail on the computer. I retreat to my viewing chair about 10 feet away when watching TV or videos.

I would go with the 55' tv. That's plenty of tv for your room. That's my two cents worth....

There is a big difference between "optimal" and just a really nice view of a tv. : ) The content is same. Often ? A lot of angst over not much ado at all.

it is up to your choice. I think the 55" or 60" is a good choice.

55 is also nice because that size seems to be in the "sweet spot"; many vendors with that size so prices are relatively low. B&H Photovideo has them on sale for under $400.