What I do when I have this problem is to turn one of the hides sideways and stick it in the corner, with the entrance towards the center of the tub. Then I put the water bowl right next to the sideways hide. That way you have a warm and cool side hide, but the water bowl fits too - I usually do this so the water bowl is on the cool side, for less evaporation in my rack. See if that works for you.

edit: Oh sorry, that may be what Spaniard meant by an "L" configuration! Didn't catch that!