How about "What dreams may come"? Haven't seen the film, so don't know if you'd mind giving the adventure the same title.
As for them getting from subspace to "our" reality, Suspiria was able to transit from a subspace domain to Voyager, and Wesley's "static warp bubble" trapped Beverley in a subspace domain, so there isn't really a problem...
"That might have been the biggest mistake of my life..."
"It is unlikely. I predict there is scope for even greater mistakes in the future given your obvious talent for them."
Vila and Orac, Blake's Seven