Sounds like you have rented the RV....so my 1st advice (stay in Anchorage and daytrip from there) would be off point.
I'd second an earlier suggestion: Go North. Or Go South. Don't cram both directions in a week. I'd suggest the 4th in Anchorage, 5th/6th in Whittier area, 7/8/9 in Seward area, 10th/11th back to Anchorage....if you leave late enough on the 12th to count it as an active day, then maybe 7/8/9 in Seward, 10th/11th in Homer, then back to Anchorage...but it will be a long day/very early start on the 12th.
IMNSHO, Denali is overrated for a tourist destination unless one spends several days there and either gets off the beaten path or takes a flightseeing trip or something of that nature. Don't misunderstand: Mount McKinley (I've lived in AK for nearly 60 years, so I'll call it what it was called when I was growing up) is spectacular, the surrounding country is incredible and for a backcountry experience, it can't be beat...however, while RVng in Denali is different than other places, that ain't the best way to see the country; Nice drives to the CG's, different scenery, but the true beauty is not seen in a 1-day trip.....and Glitter Gulch is just obscene and an insult.
So...for a short trip, I'd go South. As I said, IMNSHO.