By the sound of it you HAVE trained the pup pretty well. He has learned that it is a bad idea to eliminate while you are watching him and waits for your attention to be diverted.
If it is really too cold outside you could start the whole process again using dog litter, there are several on the U.S. market - look in the canine press for more details. When the weather improves this can then be gradually moved outside and dismantled until you are using a sprinkle of litter on the ground where you want the pup to go.
You and your husband must relax about this issue, though. It is annoying and frustrating but the dog is picking up the tension and this is reinforcing his decision to eliminate quickly while your attention is diverted. Totally ignore mistakes and the dog while you clean up. Give cuddles and treats as soon as he performs correctly.
Good luck with it, keep warm and let us know how you get on.