As instructed, I had follow up questions, so I am putting those in same thread on EZE from yesterday

I have a RT booked ( first leg affected return is fine) departing EZE Nov 1, to IAH then on to LAX

Because EZE can't accommodate wide bodies for a two week period around late Oct / early Nov I need alternative

Looks like Avianca is no longer a good alternative as it was a few years ago because apparently it's now two stops to get to LAX

Copa might work they only operate 737Max EZE to PTY and same PTY to LAX

Can a united ticket agent handle this change the best for me since I now can't use first leg of a purchased RT ticket?

Meaning, just change the routing and metal for the Nov 1 leg?

If I try to do this online, Copa flights don't appear as alternates only Avianca

They indicate there is no fees to make changes because the United flight is considered canceled.

Will my Gold status allow me to get E+ on Copa fee free at booking?

I know they're still a Star Alliance partner

Finally, what other Star Alliance airlines can get me from EZE to LAX?