Had to reorder a 25 ft HDMI cable as the 10 ft one wasn't quite long enough. That came and I've now hooked it up. IT WORKS!

But there are a couple issues.
1. The Windows screen fills my 65 inch screen. But the icons and text are too small to read from across the room. How do I fix that?
2. I tried one of my IHOG's, Mystery Trackers: The Black Isle. The picture comes in full screen, but half the page is missing. The right side of the picture is just a black area. You can see where it cuts the detective's badge neatly in half in the title page.
Assuming I can get the other half of the game to appear, I'm wondering how I'm going to be able to read the text on all my programs, and in my games. If I use the TV screen strictly for playing IHOGs. I'm still going to be spending a good bit of time at the computer desk and I won't be able to read any text in the game.
Any advice on how to fix the size issues?
Edit: I spoke too soon. I've tried a couple other games (newer) and they are playing fine with big full screens and large text. And I've gone into the control panel and pulled up appearance. I've enlarged the font and icon size to 150% and that has made some improvement..Some programs I can enlarge the font size to a readable view, others I can't. So I will go back and forth to the appropriate monitor to do what I need. It is good to know that now I can play most of my IHOGs on the big screen with my feet propped up.
My graphics card has 2 hdmi ports, so I can switch displays as needed. I want to thank everyone here again for this great advice. Now, how can I get Black Isle to display fully?
2nd Edit: Correction - I only have one HDMI port on my graphics card. But I'm going to use an HDMI Splitter to change the display on my computer/tv. I think I may have one or I can buy one.
As for Black Isle, I changed the resolution on my TV display from 3180 x 2160 down to 1920 x 1060 and it's made a world of difference. I never dreamed I could have that kind of resolution from my computer. Now Black Isle shows completely and the text is very easy to read. Also my other programs are very readable. I keep learning new things about my computer.