I have made the trip a time or two solo and it worked OK for me. Sometimes my wife didn't wish to make the vehicle trip, a round trip and so she might fly one direction or the other and meet me somewhere, usually in Anchorage. The last solo trip I did was about in 2005 as she had a family reunion in Colorado, so flew back there for that and then back home to Florida. I stayed in Alaska for another month or so as she headed south.
I found I needed to plan my next day's travel the night before, more than when she is along and can do some of the map navigation as we move down the road. Another thing I found is I had to make more effort to stop and see "stuff" as I was driving along. I tend to be an early riser, so when solo I was/am often on the road by 6 or 6:30 AM and will have made 300 miles by noon.
I think I had made 4 or 5 round trips to/from Alaska prior to my wife and I getting married, In Anchorage in 1973, so doing the trip solo didn't strike me as being too different now in later life. While I tend to prefer, having someone along on the trips, etc. it is still a great trip by myself. I have made most of my small aircraft trips to Alaska, from the lower 48, following the Alaska or Cassiar Hwys by myself. But most of those were just to see how quickly I could get plane delivered and head back outside to pick up the next one to take north.
More evening planning, taking more notes of the next day's locations where I wanted to stop, and having most of it accessible to the driver's seat. Especially if going through any large towns was involved. I like to write down any highway changes on post it notes and put them in my shirt pocket or stick on the dash for easy viewing.