I'm on a bit of a card-based mechanisms kick right now, but I'm wondering if it might work for solo gaming to get a good balance between randomness and "continuity".
The idea is to make up a series of cards, each of which describes an encounter. So one draw card per room. The continuity would come from having the content of the cards relate to each other to some extent – so for example having a dozen or (however many were appropriate) cards all describing encounters with orcs, if you were exploring an orc cave complex. Then maybe a few 'wildcard' encounters added to the deck for interest's sake.
An advantage, too is that you could have a lot of the info needed for the encounter written on the card itself, such as stat-lines for the critters, treasure, or whatever. Some of that, such as treasure recovered could be left random, or semi-random, and only rolled for after the monsters were defeated.
With the treasure listed on the cards (or at least the randomized range listed), it would allow you to make sure that there are treasures to be had where they are appropriate. You could also use the average treasure on each card as a factor in the deck design, so the adventurers couldn't get crazy amounts of loot, but if they do well they should make a profit.
There are a couple drawbacks, though. It could be a bit time intensive to begin with for preparation, since you would have to make the cards
Although these days a decent computer and a printer that will handle card-stock will make the job easier.
Another problem is that with solo gaming the player usually also does the prep-work, and so reduces the suspense that is the core of dungeon-crawling. One way to reduce that problem is to have 30-50% more cards in the deck than you have roomss to explore, so even though you know what went into the pile, you don't know what will come up or where. Making the extra cards increases the prep-time, though
Sorry for the run-on post- kind of thinking out loud! I think making a set of cards could add something fun to your games, though.
Looking forward to seeing your next delve, regardless of whether or not you use cards ;)