We've never had customers letting us know of any problems when getting out more than £15k in cash other than having to book it a couple of days in advance [though we'd normally suggest a bankers draft but it's surprising how tight some people are and refuse to pay the £20 fee or whatever the bank charges ]

But tbh why bother?

Just buy everything you need as and when If it's a savings account and a pain in the arse to get money out, just open a current account with Abbeys and transfer it instantly