Diversified investments mean you will see much less of a drop (or even a rise in local currency). But let's think through the case that stuff in the UK drops b

Diversified investments mean you will see much less of a drop (or even a rise in local currency). But let's think through the case that stuff in the UK drops by 50% and you're entirely invested within the UK. Instead of having "a few hundred thousand" you'd have somewhere north of £100000 (depending on what you mean by 'a few'). That sounds to me like it'd give you some security, or help a move to another country.