For my taste, that is clearly too much credit.
Yes, teacher, yes, good equity. Still, 750k€ remain to be financed with ~5.4k€ net income. During parental leave with child 2, that is likely to be much less, then it's about ~4.8k.
About 40% goes just towards the loan, with the operating costs of the house you are probably at around 50%. What happens in the second year with child 2 when there is no more parental allowance? Will your wife work again then? Who will take care of the children?
The 2 days/week with grandma – as one writer before me already mentioned – will certainly not be enough for your wife to have the flexibility for part-time work. Much more likely your wife will still work 4 to 5 days. So, care costs of X€ are still missing.
That would be too much for me.
On the other hand, for my feeling, the ancillary house costs of 705€/month (adjusted for reserves) are set way too high. Especially the items heating (180), water (120), and insurance (100).
Not to be misunderstood, if both of you work full-time again, that should be manageable without problems, but the next years will be tough.
That you currently need significantly less is probably mainly due to Corona.
But 300€/month for activities INCLUDING VACATION is somehow baffling to me. What about going out to eat, then relaxing in a bar, or a concert or even a short vacation? Skiing? other hobbies? I know, you can put all that aside sometimes, but not for years. If you don’t do any of that, you can naturally ignore this paragraph.
My advice would be to calculate it again carefully and possibly work with flexible repayment. Meaning, pay a bit less per month now and consistently save the rest for special repayments if possible. If it doesn’t work out, at least it won’t mean the end of the good things in life. Then massively increase the repayment when both work full-time again.
I know people don’t like to hear that, but better now than later. Living and especially working just for the house is in very few cases good.