Okay so Luny has been doing well alone in the house (except for peeing on and then tearing up the newspapers I leave on the floor by the door) while I go to work. After an inital anxiety attack (fewer and fewer howlings), I figured he just went to sleep in one of several doggie beds. However, I've suspected that he was sleeping in my bed while I was gone these past couple of days. He has never shown any inclination to get on the bed while I'm home - he's always headed right for his doggy bed which is by the heating vent. But I thought I could see paw prints in the bed covers.
This morning confirmed it - after letting him back into the house after peeing, I was doing my morning ablutions in the bathroom. When I then walked into the bedroom, there he was snuggled between my pillows ;). You should have seen the look on his face when he realized that he was caught :D. He tolerated my teasing him and then went and curled up in his doggie bed. The little sneak :p.