Just wanted to concur with others... it can more than handle cold so outside would not be a problem, full light would be more important right now to help for a good spring bloom... outside being the best for light... and keeping waterings to a minimal and dry from rain would also be good for it, although as philip says some watering is good... and yes agree you should repot for sure.

I forgot...

Yeah, they do best in bright indirect light. Do not grow them in full sun, particularly if you live in an area where the sun is very strong.

If you can grow a Cattleya, that is how bright it should be for Den kingianum.

Den. kingianum on lava rock?
 

Just curious if den. kingianum could be mounded just on red lava rock if it's growing on the rocks in wild?? Mine I bought in sphagnum and need to repot ASAP as well.

You will need to adjust your watering to keep the plant hydrated if you are growing it on rock.


Welcome to the forum!

Most orchid lithophytes (those that grow on rocks) grow with their roots reaching into cracks and crevices where organic detritus collects (and where it is also cooler) Even if some roots are on exposed rock, you can be pretty sure that some are reaching down to moisture and organic matter in cracks. I grow rupiculous Laelias in pots with gravel at the bottom, a thin layer of potting soil about 1/2 to 2/3 of the way up, then finishing with more gravel. That fairly closely mimics that rock-dwelling environment. For a Den. kingianum, though, bark works just fine and is a lot easier.(though I suspect that the "rupiculous" treatment would work)