What's guaranteed to happen is that if you double the blocksize right now, we'll see nodes dropping faster than allies in normandy.
Unfortunately, there is no way to scale anywhere notable on-chain, it's just not realistic, unless of course, you don't mind bitcoin being hosted in centralized hubs, which would kill the point of bitcoin.

Objectively, segwit is the best thing we have now. Those not supporting it are simply not aware of the realities we are dealing it, or they are, but don't care that bitcoin's network becomes centralized.

Sooner or later, segwit will be actives. Even if the morons push a blocksize increase, they will quickly see the blocks full again and realize the futility of scaling on-chain through simple blocksize increases without other methods.