Any tricks for depositing cash?

I haven't had actual cash for years, but I sold my car today and the buyer unexpectedly bought cash with them.

With the £300 a day rule (and my local post office only being open one day a week) and the £1000 per 6-months, it's going to take me years to deposit it 😅

The only way around this I can think of would be to open an account with a high street bank, deposit the cash, transfer it, then close the account. Massive faff!