Until you NO LONGER get joy out of having them, I would not get rid of them. I may control that impulse to add more, but not get rid of. My dad used to say, if it is not in the way, and it is not costing you anything to keep it, why get rid of it. If you are in a financial bind, or they are a burden, that is a different story.
Having said that, I do have a plan in place.
If I precede my wife into that dark night, she has instructions on what is to be done. It always saddens me to see estate auctions or garage sales where you KNOW someones passion is being piddled away at pennies on the dollar of it's true value.
First, my completed models are to be offered to my father (if it is still alive) and my children to pick from. I doubt my wife will want to keep any, but she surely can.
Next, my tools and supplies (of which there is enough to start a small hobby shop) are to be offered to my sons, one who is just now starting to show an interest in figure modeling (always hoped he would be a car guy, but is is 26 now, so not likely), my middle son who has little to no interest, and my youngest who at this point is still too young to build full glue kits, but loves cars and has built several snappers. (huge age gap between oldest and youngest)
Finally, the kits. I do not have quite the stash that some folks here have, as I was not always in a position to simply buy to add to the stash, and I really only bought what I thought I would build, or could kitbash/take parts from. This still leaves me with 300+ kits. First, let my boys have their pick. Anything that remains, are to be given (that's right, given) to a fellow modeler that I have known for years (should he still be alive) that I have a great deal of respect for. He is not aware of this. If he is gone, or chooses not to take them all, the remaining are to be donated to something like the Cub Scouts, or a youth club, where they may have some impact.
Keep in mind tho...I DO still plan on none of the above happening, me living a VERY long life, and building ALL my models. ? But you know what they say about plans....