Two questions, both regarding bank requirements for renewing an Extension of Stay based on Retirement (I'm British):

1) I have 800K in two fixed term accounts (400K x 6 months & 400K x 12 months), the money has been seasoned for 2 months. The money is accessible, but I would lose any interest if withdrawn early. When I go to renew my extension of stay, based on retirement, at CW is it sufficient to take the original books and photocopies confirming the deposit/maturity dates or do I need to somehow update the books on the actual day I renew?

2) Regarding the letter from the bank, can this be issued 24 hours in advance or must this be issued on the day of application?

Many thanks in advance