If you were from US, Id recommend you get a zipcar/getaround account or rent a car for those few times you will need to drive down to Palo Alto/Mountain View et

If you were from US, Id recommend you get a zipcar/getaround account or rent a car for those few times you will need to drive down to Palo Alto/Mountain View etc. However since you are foreigners, I have no idea how the insurance aspect would play out. If you go the rental route, try to see if you can get a credit card in Denmark that would cover car rental insurance overseas, otherwise you would have to pay daily car collision insurance which sometimes costs as much as the car rental itself.