Yep, you are cramming in too much. Driving in AK does take a lot longer than you think and July is the worst time for congestion. Don't count on buses running on the 4th or at least a reduced schedule. Cabs are plentiful, but expensive. Most of Anchorage you'll care to see is downtown, so just stay at the Captain Cook Hotel and walk around. Nice hotel and even if it costs more you won't need to rent a car. Just a cab from the airport, they might even have a shuttle. Maximize your time in Denali if you want to see scenery and wildlife. Take as many trips into the park as you can. The Kenai Fjords tour out of Seward is the next best wildlife and scenery opportunity. But I would pick one or the other. Don't spend your whole trip behind the wheel and following a motorhome. And you better start making reservations now, for the time of year you will be there. And expect lots of people. Keep in mind though that Denali means great scenery and wildlife, but riding a long time in a tour or school bus, can be tough on kids. It is however, your best opportunity for seeing wildlife, especially bears.