I have not found an ultra-compact case yet, but for now I am using this old Aliexpress Spark case (17x17x6,5 cm).
I just cut out the moulded inlay, and the Mini + RC with sticks now fit snugly! :)
Mavic Mini: 140 × 82 × 57
RC: 145 x 77 x 35 (ca. 245g)
DJI Combo Case: 270x195x85
PgyTech...