I just wanted to share what happened because its a good thing. I have gamepass and XBLive. My subs were set to expire in the beginning of next year 2020. Apparently if you upgrade to ultimate and you have time left on your other subs.... that times gets added into the GP ultimate sub.... sounds pretty fair right? But when I did the upgrade for a dollar my Sub was extended until March of 2021????? Did Xbox take the time I had left on both subs and add them together... I dont know. All I know is I upgraded for a dollar and now Im all set until March of 2021 GP Ultimate baby!!!!!!!

This is where I got the tip.

https://www.cnet.com/how-to/deal-on-xbox-game-pass-ultimate-free-game-pass/?linkId=68821640