spyguy :
So if I clone the boot ssd onto the larger 860 evo it wont cause any problems with windows right? I know you said Ill have to fight to get it to boot if my other ssd ever fails, but until then it wont cause any boot issues just being on the evo?
I've had systems where it caused no issues. I've had systems which I couldn't get to boot off the proper drive until I deleted the extra Windows installation. I've had systems where it caused no problems for months, then suddenly it got upset at there being another installation of Windows on another drive. That's why I called it jealousy.

It's just unpredictable.
So I can't really say how well it'll behave in your case. You can try it, but be prepared for it not working.
If you do do it, I recommend changing the desktop image of the non-used Windows install to an image that says "THIS IS THE COPY OF WINDOWS ON THE 1 TB SSD." That way you'll immediately know if your computer decided to boot off the other copy of Windows.