Thanks for the tip Pesala. After your suggestion, I looked at Windows Panel as a replacement for the Tab Bar but I still prefer the Tab Bar (in vertical orientation)... I've been using Workspaces feature a lot lately (to separate different topics I'm browsing/researching) and I like how the Tab Bar shows only the tabs from the current workspace (helps me focus on the task at hand :-)).
Windows Panel's tree view of all the tabs organized by Workspace is nice too - and it's really convenient how double-clicking on a tab in Windows Panel, automatically changes the Workspace in the Tab Bar - so now I use both. Tab Bar for normal switching and Window Panel for searching for a particular page and changing quickly to that Workspace. Vivaldi really is the most beautiful browser out there!
I have a wide monitor so Tab Bar on the left and Panel on the right help "frame" the webpages in the middle of my view when the browser is maximized and when it's not maximized, I just collapse the Panel and it works great. If I need to have the browser window side-by-side with another, you can even re-size the Tab Bar until only icons are showing (though I do wish there was a button to quickly switch between minimum and "normal" size)...
Anyhow... Neither Panels not Tab Bar sit "outside" Navigation Bar or Status Bar - so it doesn't really help me to use one instead of the other. What I'm looking for is a way to make both Tab Bar and Panels to be the "outer" frame so that Navigation Bar and Status Bar are framed by them (not the other way around) - and, that way, they would be the same width of the webpage rendering area.
Marko