Hi @GMtnezS, I tried a few session managers after I posted that message and I settled on Session Buddy. It worked well in Chrome and Opera, although with some annoyances. The majority of my browsing is in Opera but the extension came from the Chrome Store.
Then Session Buddy was completely rewritten. The extension still worked in Chrome (with many fewer features) but didn't work in Opera at all. I have been living on the edge without a session manager in Opera for a while now. Your note prompted me to give it another look and it seems they have added missing functionality and fixed the issues. It installed in Opera and has successfully stored a couple of collections. Time will tell if it works 100%.
Be sure to configure the settings to the way you want.
https://chromewebstore.google.com/detail/session-buddy/edacconmaakjimmfgnblocblbcdcpbko?hl=en