Come what may, we'll still go out tonight. In this instance, someone is saying it doesn't matter what happens, we are still going out.
Be that as it may, we'll still go out tonight. In this instance, something has has already happened which might stop them from going out, but the other person says, it doesn't matter, we are still going out. It could be that Jim called his friend and said, "I've had a flat tire on my car and I can't drive"................. to which the friend says, "be that as it may" or o.k. so, you've had a flat tire, we'll go out anyway, we'll take a taxi, or I'll pick you up, or some other solution.
Can anyone tell me what the difference between these two sentences is?