For better interest, there a few bank accounts/savings accounts, that don’t have penalties:
https://www.moneysavingexpert.com/banking/compare-best-bank-accounts/#interest
Nationwide 5% on £2500, but requires £1000 per month pay in (which you take back same day) - as long as you haven’t had an account before. Your wife can get one as well, and you might be able to get a joint one as well. So that’s £7500 earning 5%. This is just for a year.
TSB 3% on £1500, but requires £500 per mint pay in (which you take back same day) . Your wife can get an account, and also a joint one. So that’s £4500 earning 3%. This appears to be indefinite, till they change rates.
Bank of Scotland and Lloyd’s have 2% on 4000-5000 balances (still needs a pay in) and you can have multiple accounts. This appears to be indefinite till they change rates.
To do the pay-ins/payouts you need to plan and know when things happen. You also need the maximum pay in available as cash to move around. Basically you pay X in from Y, and on the same day Y into X. Ditto for A into B etc, but make sure the pairs are 5 days different to cover weekends and bank holidays backing up payments.
setting it all up can be a bit daunting, but once done it just works. Best to do it online/app, as long as you are completely happy with your devices being secure. Also keep track of when/who gets what somewhere safe.
When the bank removes/reduces the rate, make sure you cancel both standing orders in and out.
And clearly when you eventually move money out, make sure you cancel the standing orders!
there used to be many dripfeed/regular savings accounts earning 5%, but they’ve all gone now.