We are a family of 4 staying 4 nights in Munich in July. We had lots of luck 2 years ago with apartments in Italy and were hoping to find a good recommendation for an apartment rental. Looking for 2 bedrooms minimum.
Munich is tough. It's a fairly expensive city. I stayed a bit off the beaten path, but it was really nice. There are two separate bedrooms, each with a full kitchen (not sure how old your children are and whether or not that would be safe). The area is really nice, with a grocery store, pharmacy and an Italian restaurant that was quite good. I would stay there again. Here's the link: https://www.tripadvisor.com/VacationRentalReview-g187309-d5027611-SOUTERRAIN_ROOMS_WITH_BATH_750_sqft-Munich_Upper_Bavaria_Bavaria.html