Hate to break it to you fellas but Dream Theatre and similar prog sounds like haunted house music with or without the synths. Slightly less-so, yes, but still haunted house genre.
Electronic elements can and do sound great when done tastefully and not over music that uses abstract modes and keys just to be big brain.
Even their famously good riffs like the intro to The Dark Eternal Night (which sounds great, no denying that) would still easily fit as the theme for a kids Halloween show. They should get in contact with R. L. Stine for a deal.