It's certainly possible. The question is, why do the Norse kings - who seem to have seen an advantage in converting OTL - decide it isn't useful?
As for a crusade, with a POD that far back, we have rather drastic impacts on if there ARE crusades.
If you can prevent the conversion of England (cetainly doable considering the time when it likely took place) that would stop missionary activity into Scandinavia cold. With England as another option in the North Sea-Baltic Sea region there's less pressure to convert and fall into Frankish orbit.
Another good possibility would be killing Charlemagne before he launches the Saxon Wars. No Charlemagne means his use of religious conversion as a tool for engaging in political subjugation doesn't get started which is what gave the Scandinavian kings a good political reason to convert. While preventing the rise of Charlemagne won't stop someone else from coming up with that policy later if you remove the Saxon Wars and give things more time that could lead to time for conditions in Scandinavia and Germany to reach a point where there is no need to ally with the Church or the Frankish Empire.