Do it yourself for sure. If you travel alone in the lower 48, you can feel comfortable that you'll do just fine by yourself in Alaska. We've been up 5 times so far in the RV and once flying up in 2011 to see the Iditerod, and will go many times more, Lord willing. We have always traveled solo. The roads are excellent in Alaska and in planning your trip you'll find that you get a much greater appreciation for this great land and it's attractions than you would if you just were one of the herd in a caravan. The people in Alaska are friendly, helpful toward everyone, and your interaction with them will give you a much better appreciation of their state and it's attractions. Our experiences in dealing with caravanners is that they tend to keep to their own group and miss a great deal by not interacting with the rest of the people they come into contact with on the trip. RV parks are a bit on the primitive side, but water and power are available, and most have showers and bathrooms. Reservations beyond a few days in advance are usually not necessary except for things like the 4th of July in Seward or Denali and if your selected park is full, they are very helpful helping you check with others. Of course when you're solo and you find a place you like, it's a simple matter to stay longer, or leave earlier if that's your desire.
Go alone and explore. In all the trips we've made, we always find something new to do or a different place to see in Alaska. You're obviously an adventurous type simply by being an RV'er, so do your planning and research and then enjoy the fruits of your effort.
