Thanks all.
He's home by himself from 9 to 5. It's long for him, but we both have to work during the day. He usually sleeps it through and by 3 to 4, he is busy making a snow with his pee pads in the pen.
We did try to give him treats when its a real potty trip and no treat when its "fake". Not much difference... We will keep taking him outside as soon and often as he signals
and we started our daily walk, that seems fulfill his curiosity about the world outside
