My wife and I play 2 player heroquest every so often. We find that one person with all 4 characters gets really boring. Try with 2 characters, as 1 might be pushing it a little. Can always go down to 1 later on.
Alternatively you could play both players with 2 characters each, number the rooms and write the contents out on cards for each adventure (secret doors, treasure and traps on different cards), turning things over room by room. For corridor traps etc, roll a
D6 and a roll of 1 you character fell into something
More work, but could be fun.
Edit - I'm actually sure I saw an online adventure generator which did something similar - so if you have a look I'm sure you will be able to find it.