OrchidWiz says lows average 58F to 62F year round.
You are correct, but what was the diurnal range of the lows? 58-62F was the average. I always understood this to mean how much the temps could deviate from the average. It could go as low as the low 40s in their native habitat.
I believe 46F for a night should present no problem.
I suggest you take it inside. Dowiana hates low temps; it will get all sulky on you. They love to be kept on the dry side; so a porous mix that dries quickly and potted in basket or clay pot (if pot, pot on the smaller side).
I am trying my hand with Dowiana Aurea; its a seedling but i hope to see the fruits of my work down the road.