Re: Maintaining the growing blockchain ledger size in local full nodes
The same could be said about how blocks are currently shared.
The only difference would be that instead of having 10,000 nodes with the full blockchain, you'd have 1,000 nodes for each 10% of it.
And as the network grows you'll likely have more nodes anyway, so it could be 10,000 nodes for each 10%.
But the UTXO set will require a more elaborate scheme.
Currently, full nodes verify and validate each and every block to ensure that they are valid and adhere to the protocol rules. If you were to store all the blocks separately, not every node will be verifying each of the blocks. This means that nodes will never know if the blocks are valid or not. It'll just be like a SPV client.The only difference would be that instead of having 10,000 nodes with the full blockchain, you'd have 1,000 nodes for each 10% of it.
And as the network grows you'll likely have more nodes anyway, so it could be 10,000 nodes for each 10%.
But the UTXO set will require a more elaborate scheme.
In addition, how would you know which nodes would store which "10%" of the blockchain?
I don't know. If the current growth continues, and the scaling problems are solved, perhaps a doubling each year is more likely. That works out to be about 40TB in 8 years. 
But of course, the scaling solution might not involve having to store the full blockchain.
Normal users can just run a pruned node. But of course, the scaling solution might not involve having to store the full blockchain.If the current growth remains the same, I'm estimating an additional ~52.6GB per year.