I am going with Opeth as progressive. In the UK prog rock had become huge stadium bands playing music on an epci scale, such as Pink Floyd, Genesis and Yes. Early prog rock had also been very psychedellic and also crossover with folk, but that had died away into obscurity. When punk hit the charts in 1976 and really got going in 1977, prog became a dirty word in the music press. Only the very boggest, such as mentioned above survived. The chances of record companies financing new prog style bands was nil.
In the late 1970s early 1980s came the 'New Wave Of British Heavy Metal' with bands such as Rainbow, Whitesnake and Saxon. There were prog elements in the music; the solos, the fantasy lyrics and album covers. Marrillion became the first UK prog metal band that I am aware of. Other than that there was very little in the way of prog anything. Radiohead were the first band I know of who were mainstream, successful and acknowledged their prog influences with King Crimson. Initially Radioheads sound was indie rock. But as they became more successful and could indulge, their sound has become more prog rock.
Meanwhile prog in Scandinavian had continued throughout and certainly in the 1990s had become far stronger then hear in the UK. Prog metal, heavy rock had taken up the mantel that had been occupied by the stadium bands, some of which had gone almost pop, such as Genesis.
Now prog is a term that many bands, particularly in Europe are happy to have. There is still a bit of resistence here in the UK. Furthermore, as with so many genres (dance/house mucis) prog has split into many sub sections. Jazz, metal, symphonic, psychedellic, folk, heavy prog, crossover etc etc.
I am quite happy to use a very broad definition of style included in prog music. The overall definition is music that emphasises musicianship, exploring sounds, not sticking to ususal time scales and song structure (verse chorus verse) etc.
