For Toobworld, the official version of Dracula was portrayed by Rudolf Martin, first as a human warlord of Romania in a TV movie about Vlad "The Impaler" Tepesz and then as the vampiric count in an episode of 'Buffy The Vampire Slayer'.
One good thing to come out of the short-lived series 'Demons' was the declaration that the story by Bram Stoker was a work of fiction about the vampire. But even so, Stoker stole many elements from the "historical events" of Dracula's "life" during the last years of the19th Century. And these would include the "real" people Jonathan Harker and his fiance Mina Murray. Stoker used their real names, but fictionalized some of the details in their lives.
So if any adaptation of "Dracula" is even somewhat faithful to the book, we can dispatch it to some alternate TV dimension. And the version of Dracula from 'Buffy The Vampire Slayer' and the version of Mina Harker from 'The Buff Vampire Slayer' - er, I mean, from 'Demons', - can be considered the official portayals of those characters in Toobworld because they differ greatly from the novel.
Does that make any sense? It does to me, but then I'm not right in the head.
Looking through the IMDb, it looks like Mina didn't make it into as many adaptations of "Dracula" as would be expected. So it's not like we'd be tossing out a better candidate for the role in Toobworld in favor of Zoe Tapper in 'Demons'. And with her multiple outings in the role, even limited at six with the end of the first and only season, she would have had the upper hand anyway.
Other portrayals of Mina Harker on TV include:
. . . Dracula: A Chamber Musical (2000)
. . . "Mystery and Imagination" (1966)
. . . Dracula (2006)
. . . "Young Dracula" (2006)
Judi Bowker (Wilhelmina 'Mina' Westenra - a different last name for once)
. . . Count Dracula (1977)