I've been thinking about this for a while: using Ganesha's Four Against Darkness (4AD: a solo pencil-and-paper dungeon crawler) with Song of Blades and Heroes (or perhaps Tales of Blades and Heroes). What I'd plan to do is to make large card floorpans for all the possible rooms and corridors in 4AD - and to make them really large, with each graph-paper square being a 3" x 3" square. I'd be using measuring sticks, so I wouldn't worry about having squares on the floorpans, just having them all to scale. Several of each type would be required, and probably a few odd bits and bobs, so that if all the examples of a given shape were used up, more could be assembled.
Anyway, I'd play it out like this: the players each get an 100-point character (or group of characters: a leader and a couple of henchmen, for example), while the "GM" just gets the monsters that are randomly generated by the 4AD engine. Neither side knows what the dungeon looks like, as it's just randomly generated as play progresses. But the layout of the dungeon would become increasingly important, as the GM would have scope for withdrawing monsters, regrouping and mounting pincer movements. If the PCs fled from a powerful monster, then it could come after them. The odd surviving goblin or kobold might not be much of a threat on its own, but if it retreated to where larger, fiercer friends were waiting ...
I'd use the treasure-generation system in 4AD, but match experience and cash to the points system in SBH (not sure what the conversion ratio would be offhand, but I think it would be pretty simple to do). So, characters who escaped with treasure could use that to hire henchmen or upgrade their characters (improving Q or C, adding traits, etc.). That would give a nice risk/reward ratio, as there would be a real incentive to get loot and experience, but with the wandering-monster rules from 4AD, you'd have a real risk of getting outflanked or surrounded the deeper in you delved. And I gather that 4AD now features rules covering different levels.
Another tweak that would be needed would be some sort of "contents" rule. I think the best way to do this would be to have a box of "features" (tables, plinths, statues, etc.), roll 1D6 for each room, and then have the players alternate the placing of the contents, starting with the DM.
Throughout, I'd map the whole thing on graph paper as in 4AD. While I like the idea of an endless dungeon extending across a sitting-room floor, it would be more manageable if you could remove some of the rooms but have a record of them. And 4AD imposes paper-based limits on the extent of the dungeon, which would probably work well. That would entail one more tweak - an "off-board movement" rate for monsters left behind. I doubt that would occur too often, but it could be easily rationalised to two rooms/corridors - or a given number of squares - per group. All off-board models would activate in groups and move a bit faster (a bit like Space Hulk blips).
That all sounds very complex, but I don't think it would be in practice. Both 4AD and SBH are great, simple games. But by allying one with the other, you get both an excellent random-generation system for dungeon, monsters and treasure and a superb skirmish system - so that the battles are as engrossing and tactical as any game of SBH. Also, as SBH fights are often won with routs, there would be a lot of temporary victories and then a pressing need to move on. And that's exactly as it should be. Why? Because if Moria is the classic dungeon, then there should be a lot of things in this vein:
"There was a bellow and the foot jerked back, nearly wrenching Sting from Frodo's arm. Black drops dripped from the blade and smoked on the floor. Boromir hurled himself against the door and slammed it again. ... 'Now is the time!' cried Gandalf, 'Let us go, before the troll returns!'"
Anything that gets away from "room clearing" and leads to a sprawling dungeon with monsters wandering, being driven off and regrouping would be a very good thing, I reckon.