Hopefully well? However, the what-if game is generally bad to play, especially when we can't even ball-park frequency. There are always many what-ifs that can be made.

However, even when we know frequencies, we often still ignore them. What if an accident happens on the way to the airport, which is far more likely, and far more likely to be fatal, than flying on even a 737-MAX 8?

What I think is more probable than any issue with the MAXs translating to the NGs is: what-if other (recent) FAA certified planes, by any manufacturer, have undisclosed problems or systems? There's obviously a systematic flaw in how the FAA conducts certifications, so this worries me more than finding a fatal and fundamental flaw on aircraft that have been in near constant use for 20-25 years old at this point, as are many/most of the the NGs have.