You do not need to tie up any money. You can satisfy income requirement via monthly income (pension, etc). If you're from USA, that means you sign an affidavit. They may ask to see some bank activity. Point is, you don't need to freeze funds. And even if you did, you can take it out for 9 months a year.
You do not need 800k in the bank for a retirement visa. There are three methods to satisfy the income requirements. Some methods are ridiculously easy.