Positioning is important. Find a "killing ground", a location where all advantages go to us. Maybe there are traps here we can manuver monsters into. Maybe it's just the right size, has lots of room to move around. It's probably near to the entrance, or somewhere else we can retreat to.
Could also try finding another adventuring party and steal kills. Risky, unlikely to work given our lack of stealth, but worth mentioning.
There's a chance that rooms move around in the temple, much like the rest of the land does. Could allow for us to claim a section and go voyaging through the temple, so to speak.
It's a temple, and it's dedicated to the moon, so we can make some guesses.
-Going up, rather than down, leads to greater power b/c up is closer to the moon.
-There is a holy of holies, or something like it.
-The moon has phases, and this may play into the Temple. What phase of the moon is it right now? See if entering during different phases gets us different results.