I have been looking at Theia dimensions, to figure out what might be appropriate size of a Mini Theia.
Initially a bit confused as Marco's shop pages give more dimensions for full-sized Theia than for Theia Midi, but I am pretty sure I have figured it out:
Max width Theia:40cm - Theia Midi:34cm
Center height Theia:31cm - Theia Midi:27cm
Bottom depth Theia:11cm - Theia Midi:10cm
(For inches divide by 2.54

)
I believe the design limits how small a Theia can be, as Theias need to be shallower at the top than at the base, while leaving enough top depth for the strap that runs around the bag. This is a side view of my full sized Theia. I don't own a Theia Midi to compare with..
View attachment 5337670
Max width for Theia Midi is 6 cm less than full sized Theia..
Maybe another 6 cm smaller would be it would be possible for a Mini Theia, so 28cm max width? And height 23cm.
(Approx. 11 inches wide and 9 inches tall)
What do you gals think?