My question to any others buying the same smaller amounts, do you wait until you hit a self decided amount (say £50) then withdraw to cold storage? I'm mindful of multiple fees from transferring it after every small purchase on the exchange. I know its a risk leaving money on the exchange but I figure risk of loss up to £50 with a reputable exchange like Binance is acceptable to save on transfer fees.
It was true that storing your coins on an exchange is not recommended, however, I think it would be fine because it's just a small amount just like you have said, if you keep withdrawing it even if it is a small amount the fees might kill you especially that fees today was extraordinarily expensive. So yeah I think you'll be fine leaving it there for a moment then you can withdraw it to your wallet if you accumulate enough. Besides, the exchanges you have been using were Binance and we know how reputable that is.