Seeing as your file is 28 gigs, 4K would be overkill for now, I think, at least in terms of the size of that thing. Plus, many of us don’t even have the proper hardware to play such resolutions. The 4K should be kept handy for archival/future proofing.
For the time being, I think its better to just release the 1080p file that you have of 28gb size. Let us know what you think. Thanks.
P.S: Sent you a PM.