If you are planning on driving to Breckenridge, you need an all wheel/4wheel drive vehicle. It is against the law to drive up there without one. If you plan on flying I would recommend you fly into DIA (Denver international airport). There is a small airport in Breckenridge but I think it’s only small planes. When renting a car you will need all wheel/4 wheel drive.
If you can share an airbnb this might be the way to go, especially if you plan on staying longer. You will want to be close to Main street.