a couple of thousand in a bank account for a rainy day

Nothing to worry about, you have protection for up to £85,000 under EU law which will be transposed into UK law until removed (so, at least 2019).

couple of thousand in a bank account for a rainy day am I better off investing the money in safe bet stocks or bitcoin to protect it during brexit?

No one knows, you can't time the market.

Bitcoin is so volatile, you don't know what's going to happen. It's rallied 50% in just over a week which is actually a bad sign because it can plummet just as match (and it has in the past).

It just seems risky keeping it in a bank with everything being so up in the air in this country at the moment.

What risk? You have FCA deposit protection up to £85k, which you're emailed about, written to about, and backed by the UK Government. What is making you think that your money isn't safe? Literally no one else is concerned about it because the it's UK Government backed - ask your bank about it as they have been providing you literature about it in the post (I also bank with TSB).

What risk is it you're seeing?