What can we afford? - Opinions needed

In retirement age, the income will very likely be needed for maintenance measures; you can't also pay off a mortgage on the side. At least at the financial institution where I work, such things are not done, and as far as I know, it's the same at Volksbanken and Sparkassen. Either the house is paid off by the time of retirement, or there is no financing. I am also not aware that this is supposed/will change.

The lady at my bank explicitly said that she had "no problem with a small residual amount at retirement." It is handled differently. But I would also try to make sure that the house is paid off then.

The lady from the bank explicitly told me that she "had no problems with a small remaining amount at retirement." It is handled differently in different cases.

But I would also make sure that the house is paid off by then.

Ok, with "smaller amounts" that are still within the conceivable range of a special repayment, that would probably even still be possible with us. A lot can happen in 20-30 years of term. But repayment plans being designed from the outset to extend several months/years beyond retirement age is, to my knowledge, not the norm. However, I can only speak for the institutions here in the area. If credit institutions in high-price regions are already massively starting to break this former taboo, just so that even the most overblown purchase price can still be shouldered by their customer come what may, then the bursting of the bubble is probably imminent.

The house does not have to be paid off by the time of retirement nowadays. It is only important, and is also taken into account accordingly by the bank, that the available pension is sufficient for the installment payments. I recommend the current Finanztest 2/2020 by Stiftung Warentest for this. Only the conditions vary significantly between the different providers, but are absolutely attractive in the current interest rate environment. This often purely German way of thinking that a property must be paid off by retirement is therefore outdated, but can still make sense in individual cases (lack of private provision, low statutory pension, etc.).

It's fine if the [immo] really becomes 450 and your equity doesn't melt away

Common standard financing 500 thousand euros with 2% repayment and 2% interest. Runs for almost 35 years. If you take it out at 35, it will be tight until retirement. Sure, special repayments, but you don’t have to...