The answer is simple, Blockstream will apply SegWit and LN to another Alt coin like LiteCoin and it will function as a true Peer-to-Peer digital payment system, and Bitcoin will loose users to whatever Alt coin that incorporated this. So you will have a 3rd division in this community.

Bitcoin will then serve as a store of value for the hoarders, until it lose enough value that they too will also abandon it. Miners cannot survive in a scenario where mass hoarding takes place. No tx's = No mining, and NO mining = NO Bitcoin.