...would Bitcoin survive and adapt under a global ban scenario, or would adoption slow down significantly?
Yes, it may affect the price with very huge effect on it but as long as the nodes are still there operating, bitcoin won't die and will continue to exists. Of course when bitcoin is banned, cryptocurrencies will the same too and will suffer the most, thus some or most altcoins/tokens, worst all will die and end its operation after few months of the ban.