I'd like to know if there is something I can do to close the gap or hide the gap in the blinds. Obviously, I can measure properly and purchase new ones but really trying to avoid that.
I've also thought about curtains, but it's also something I'd like to avoid. Are there any solutions to this?
Here is another photo zoomed out. 
You could try applying something to the actual window, like a fake wooden "pane split" whatever the real name for that is. Put one on the inside and the outside, so it doesn't look weird. Just make sure the wood is weather proofed. Even the inside one will likely see decent humidity and moisture some seasons.
https://www.thistothat.com/cgi-bin/glue.cgi?lang=en&this=Wood&that=Glass
Options for the right adhesive.