TeamViewer is a great product for the stated need. It is easy to use and accessible. If you're repeatedly accessing the same machines it remembers the partner IDs, too.
Also, NVDA with the Golden Cursor add-on can be very handy for accessing sites with lots of unlabeled controls. You may still need sighted help for the setup.
Brian - Windows 10 Home, 64-Bit, Version 1809, Build 17763
Explanations exist; they have existed for all time; there is always a well-known solution to every human problem — neat, plausible, and wrong.
~ H.L. Mencken, AKA The Sage of Baltimore