Is it sensible to use a savings book as collateral for purchasing a weekend house?

Dear congregation,

I am facing a "luxury problem." I am planning to buy a small, old weekend house and could provide the total amount "in cash," that is, without a loan. However, the money is in an older, tied-up, and well-interest-bearing savings book, and I do not need the entire amount.

Therefore, my question to you: Since I can offer more than 100% security "in cash" for the loan amount, what interest rate "can I at least expect/demand"?

PS: The whole thing takes place in Austria, but I assume that the conditions in AT and DE are relatively similar.

Best regards

On the one hand, it is quite possible that there are different interest rates in Austria.
In addition, there are surcharges for real estate loans under 50,000€.
You did not specify how much your loan should be.

100% cash security is probably the best protection for a bank.

You can only find out the exact interest rates through a conversation with banks or financial advisors.