Can a multiclassed Sorcerer/Tempest Cleric use Charisma instead of Wisdom to determine save DC for the Wrath of the Storm feature?

I have a question related to this one:
What is the DC of the Tempest Cleric's Wrath of the Storm feature?

Since the rules don’t specify how you calculate your DC for this ability, could a multiclass Sorcerer/Cleric use their Charisma instead of their Wisdom modifier?