MakeMKV from https://www.makemkv.com solved it for me.
There's been a few times I shared thismovie.mkv and noted it was from thismovie.iso or thismovie.torrent and plenty of others will download it.
While you get used to that program, go ahead and download what you wish, knowing you can make it be a single mkv file when you're ready to do so!