If you put nearly everything in your Gmail or other inbox, why not send long articles there for later reading? Free text-stripping and mailing service toread offers a bookmarklet that sends whatever you click right to your email.
ToRead was around way back when — or, at least, way back in web years — before free webmail offered such robust storage and smartphones offered instant email reading. ToRead has kept up with the times, too, offering iPhone/iPad-friendly bookmarklets and honing its text simplifying powers. Plus, as commenter PrarieMoon points out, it's a smart way to save the text of articles as they are at that moment, regardless of later edits or site shutdowns.
ToRead (technically "toread") is a free service that should work from any modern browser.