Alright, so here's the scenario; a slightly saner Ivan IV does not destroy Novgorod but instead kills the chief aristocrats only. This leads to a Novgorod that is still strong, but strongly anti-Rurikid.
Fast-forward to 1598, where the ASB element of the story takes place; the weather conditions causing the Time of Troubles happen to a more limited level, causing the Godunov to continue being loved. This causes Tsar Boris Godunov to be able to marry Xenia Godunov to a Swede (my favourite option is Gustavus Adolphus) and marry Fedor Godunov to one of James I's daughters.
Once again, fast-forward, this time to 1605. When Fake Dmitri I is about to reach the gates of Moscow, a former oprichniki, Ivan Shuisky, warns Tsar Fedor Godunov to flee north to the anti-Dmitri Novgorod. Fedor agrees.
A northern Russian/Uralic/Tatar state is established and survives due to English and Swedish (later general Protestant) support, leading to a conversion of Northern Russia into Protestantism, while Michael Romanov still becomes Russian tsar in the south.
Is this plausible, and what would be the consequences of this scenario?