Many thanks to vman81 for their excellent design!

This solution requires drilling into the Raspberry Pi keyboard. See below for assembly notes.

Notes:
I had to split the hinge into 2 objects as the Mini 2 build plate is small. I added a physical shutdown switch below the screen for fun even though you can do this with the software.

Material used:

• Raspberry Pi 3B+ (or better)
• HDMI 5" Display Backpack - Without Touch
  Adafruit also sells a touch version if you are so inclined. I opted for a BT mouse that I had lying around.
• Raspberry Pi Keyboard
• Adafruit 1000c Powerboost
• Lithium Ion Battery Pack - 3.7V 6600mAh
• Shutdown switch
• Power switch
• Power and HDMI cables were purchased on Amazon - they have tons of options of course.

LulzBot

Mini 2

Yes

Yes

0.18

50-100%

• The hinges are screwed into the keyboard with flat-head screws. I recommend disassembly of the keyboard to verify screw hole locations.
• Some soldering is required for the power supply.
• The battery is held on with zip ties and 3M double-sided foam tape.
• The screen and Raspberry Pi are through bolted with M3 bolts available on Amazon. I also used adhesive foam pads as "stand-offs" as both are not flat on the backside.
• I also used a dab or two of hot glue to keep the wires in place.