I've taken 20+ trips on the Alcan plus a couple flying. It's really easier when flying to have a sidekick....with the current rules on border crossings, I wouldn't even attempt the flying trip today.
...but of the driving trips, only 5 - 7 of them were with someone. The rest were solo. I entirely agree with Joe....if you're solo, take the evening to plan where you'll go and where you want to stop the next day.
Other than a bit of additional evening planning, absolutely no operational reason not to do the trip solo. Not sure if there is any issue with driving/working your RV solo, but the trip itself is not a big deal.