This morning Hyundai of Germany did a FB live walk around video of the Ioniq 5. Part of that live feed showed some basic dimensions of the trunk area as well as video of the Frunk. Here are some time stamps of the below video that does over the frunk and trunk area (twice).
More info on Frunk starts at 44:10
Trunk Size info starts at 45:21:
To edge of rear seat folded down (seat all the way back):
164cm (64-9/16")
To back of front passenger seat (looks to be all the way forward):
196cm (77-3/16")
And again at 47:35
To back of rear seats (all the way back):
97cm (38-3/16")
Between Wheelwells:
105cm (41-5/16")
Note: They showed the front passenger seat (headrest removed) and rear (40 split) folded down starting at 42:38.
More info on Frunk starts at 44:10
Trunk Size info starts at 45:21:
To edge of rear seat folded down (seat all the way back):
164cm (64-9/16")
To back of front passenger seat (looks to be all the way forward):
196cm (77-3/16")
And again at 47:35
To back of rear seats (all the way back):
97cm (38-3/16")
Between Wheelwells:
105cm (41-5/16")
Note: They showed the front passenger seat (headrest removed) and rear (40 split) folded down starting at 42:38.