Need advice on trading my entire vintage card collection

[AGuinness]

That's a junction in the road that many, if not all, collectors will come to. And finding the right balance of keeping what you have collected and the consideration of what would be best for your heir can be tough.
It strikes me that maybe there is an answer in between trading everything or keeping it all. First, even if your son is not a collector, there may be a set you have that he may want to keep (your first, your favorite, his birth year, etc.). While inheriting 50+ sets can be a burden for a non-collector, having one set that was nearest and dearest might be a great keepsake. You could then trade the remainder for some key cards in the hobby that would be easier to sell.
In the end, getting on the same page with your son about your collection - whether that's giving him enough info to be able to sell it all when he inherits it or even understanding that he doesn't want to deal with it and it would be better for you to handle it before then - would be a very productive step in the process.