Is there a way to predict somehow the required storage for a specific blockchain?
This depends on a number of factors,

1) The amount of transactions 

2) How the blockchain will be compressed in the near future.

Now as i'm not quite familiar with the altcoins you stated, I can't go in depth about their compression development, but it would be fairly easy to find out what the MAXIMUM size of the blockchain could be.

Simply calculate every block as if it would be filled up with transactions ( maximum size), and multiply that by the amount of blocks  for/until the next year.