Would I be granted a husband in Jannah based on my own level of righteousness, rather than being the spouse of my current husband who is more pious and would likely be in a higher level of paradise?
When both husband and wife are in Paradise, Allah Grants both of them the best to make every one from them as the best for the other. Your husband will be granted with the best that will not even dream, and you will see him as the most wonderful man in the Paradise, same you will be granted the best that your husband will see you as the most wonderful woman in the Paradise.
'Wassalam.