I found a workaround via Reddit: https://www.reddit.com/r/iOSsetups/comments/hfcchb/ios_14_how_to_stack_large_widgets_on_top_of/
Specifically, this:
- Create the large widget in the widget slideover page (not an actual app page), create another widget and stack them on top of each other in the widget slideover page.
- Once that's done, move the stack onto an app page.
In this way, I was able to create multiple copies of the same widget (Things) and then stack them and move them over to the home screen page alongside other apps/widgets, and then edit the stacking of Things so that it shows different sections (Today, Upcoming, Project 1, Area 3, etc.).
In case it's not clear, by "slideover page," we mean the page that's to the left of your leftmost app page that has your pre-iOS14 widgets. I find all this confusing; Apple could have done a better job with marketing and terminology because even on the slideover page, you can create pre-iOS14 and iOS14 widgets that are all compatible on the slideover page, but the pre-iOS14 widgets cannot be moved over to the apps pages because -- I presume-- developers have not yet created that compatibility or updated their apps to serve as widgets.
As for my newly created 14 pages of apps, I'm taking this opportunity to do a massive weeding. What makes it easier in iOS14 is that when you delete/remove an app, you do have the option of moving it to the App Library so even if you're hesitating about deleting that app you never use but find interesting and the little hoarder in you wants to hold on to it, well, pffft-- zap it to the App Library then. It's off your pages, but still on your device. Less clutter, but same functionality.