I assume you see Bitcoin as a store of value rather than a transaction currency. The higher the price surges in the face of the fees discussion, the more I tend to agree with you (and the more the argument of BCash proponents vanishes). Perhaps Bitcoin is not mostly about 'near zero fees' transactions but about decentralisation. If that is true, your prospects aren't that outlandish. And indeed, you are not contemplating extreme scenarios yet.

For some more musings on cryptocurrencies but mainly fiat currency and the prospects for the dollar, see: https://www.goldmoney.com/research/goldmoney-insights/monetary-update-for-the-dollar?gmrefcode=gata