No significant effect on BTC. At least I hope not. The scenario where people rush out to buy BTC en masse to escape a falling currency would be a nightmare currently. The network can't support that many users and there are no mature, trustless off-chain solutions yet. Mass adoption of BTC at the moment would mean mass adoption of IOUs from exchanges and payment processors, not on-chain BTC.
Well the network didn't feel any impact now when China speculators and investors are using it as a getaway from CNY devaluation, so i doubt it would be a "massive" impact,
and also; the users would buy from exchanges and keep, as store-of-value , which would not make them network "weigh".
I for one hope to some extent that this happens, given the fact that EU is already becoming bitcoin-friendly in recent events.