Michael Dunworth has time locked half a Bitcoin for over 100 years and has revealed the private key. He talks about it in this piece.

I'm not sure if it's a good idea but just to entertain the idea you could do something similar by time locking sats to be released at a certain block height.

I personally think its too far away. Bitcoin is changing fast. What it looks like in 20 years could be completely different to what we experience today.