If the resorts are Contemporary, Poly, or GF, check to see whether MK has morning Extra Magic Hours. When I stayed at POFQ, I had a 7:30 ADR at Kona Cafe in the Poly. Buses starting running from POFQ at 6:30. I boarded the first bus for MK. I could have gone to MK and/or TTC, then taken the monorail but, as an added bonus, since I was the only passenger, the bus driver radioed ahead to dispatch that he would drive me straight to the Poly, which he did.
During that same week, I had an ADR at the Contempoary for dinner on one day and at Boma for breakfast on my check out day. I just drove. As you may know, there are gates at the entrance to every resort. At the time, they requested my KTTW card for proof that I was staying at another resort. Perhaps they scan for MBs now. But you can still request an KTTW card anyway. I, personally, wouldnt spend the extra money for a taxi.