Thank you both of you,
Impetuous and in a hurry, I went ahead and copied the entire vivaldi folder over., before I read your two responses.
It worked with one hiccup--I lost the only two passwords that I had saved, both for email accounts. I had to reset these--no problem.
If I had followed DoctorG's advice, It probably would have gone perfectly.
Perfect is an absolute. Something is perfect or it isn't. There are not normally degrees of perfection.
But in this case, I can break rules. The migration went mostly perfectly.