Old home savings contract - what should you do with it?

Hello.
After the construction planning, we are currently taking care of the financing.
In the process, I have come across an old home savings contract with a home savings sum of 15,000 euros (already saved 7,300 euros) from 2006. It would be ready for allocation, but I just got a shock at the demanded loan interest rates.

We already have a rating number of 55 points, which means:
Interest rate 4.25%, effective annual interest rate between 4.47% and 5.03%.

Our bank would offer us, with 20 years fixed interest + 5% special repayments per year, 3% repayment, and a loan of 380,000 euros, an interest rate of 1.8%.

Now the question for me is what to do with such an old home savings contract. At the time it was concluded, interest rates were significantly higher than today. Accordingly, the contractually agreed loan interest rates back then would be very unfavorable if the home savings loan is used.

Honestly, I have no idea what to do. I could...
1. continue to pay into the home savings contract and receive 1.5% credit interest. Although eventually a termination by the home savings bank would certainly have to be expected.
2. I apply for the allocation of the home savings loan with the high interest rates, hoping that we might get better interest conditions with the main lender as a result (possibly an improvement of one 0.1% level could be possible).

What do you think about this? Maybe you also have other ideas. I am curious what can be done with such old home savings contracts in new construction...

I am doing 1. With standard savings, which makes it difficult for the Sparkasse to terminate.

If you can continue to do without the 7 TEUR 1. If it gets tight after all, it's quickly flattened.

Everything else is nonsense.

I would also continue saving if you can do without. Even upon payout, you do not have to take the loan.

The following text is to be translated COMPLETELY and reads: X

simply save the super good interest rate