However, I don't think that there will be any mass protests or anything if governments simply start banning the usage of Bitcoin within their countries, people will try and use it behind the scenes without letting anyone know so that they don't have to face any legal consequences but they will barely raise their voice for it.
Only if they're lucky. In a country where something is "illegal" you must exercise extreme caution to avoid getting caught. Not everyone is brave enough to do this, especially if the country has an autoritarian regime (eg: North Korea and Russia). Fortunately, this won't affect Bitcoin due to the way it was designed. If a country rejects Bitcoin, others will support it with open arms.
In the worse case scenario, we can run nodes and miners in space (the Moon, maybe?) to help preserve the BTC blockchain for generations. To take down Bitcoin for good, the whole Internet must be shut down. And we all know that's virtually impossible to achieve. Who knows if oppressive governments will change their mind about Bitcoin in the future? If you can't beat it, join it.