Streaky, I did something similar a couple of years ago when I moved from a rambling, 4 bedroomed house to a tiny 2-bed bungalow.
My husband is the sort of hoarder they make TV programmes about and had, literally, rooms piled up with "stuff". I was a collector of vases and jugs, many of which were displayed on any available space, plus I still had all the assorted pictures and bric à brac bequeathed to me on my father's death. Most of it had to go!
I packed up my precious collection and took it to a charity shop some distance away (I couldn't bear the thought of passing a local shop and seeing my stuff in the window; I might be tempted to buy it back!). It was a fantastically liberating experience! Looking at the empty space I'd created filled me with enthusiasm for getting rid of more clutter and, gradually, good stuff went to charity shops or Freegle; junk went to the tip and a modest core of stuff to keep moved with us.
I love living clutter free and OH is getting used to it. He has a 2-car garage to accommodate 1 car and his man-cave stuff but no more piles of stuff in the house. Storage space is restricted so, generally, something new coming in means something else has to go. All I can add is that I wish we'd done it years ago!