I have had this little guy since last March. He was brought to a shelter with long matted hair, he was extremely scared, would not leave his crate or speak at all. The shelter told us he was 3 years old. Wrong. He was 3 months old. Anyway, we brought him home and he did great - for the most part - with potty training. We moved about a month ago and he is very stressed out. He goes wherever he wants now. To top it off, since the cold weather has set in he refuses to go outside any longer.
I am madly in love with this little guy and would appreciate any suggestions.

Jae, a change in environment is very confusing to a dog. They are very much creatures of habit. When their circumstances change they don't understand what is happening, get scared, and can very easily back slide with their training. Although your dog was housebroken at your old place it doesn't mean he automatically understands that he can't potty inside at all. It appears he understood he couldn't potty inside where you used to live. He is still a puppy after all. :) That poor little guy. The best way to handle this is to go back to square one and potty train him as you did previously. He should respond quickly to a little reinforcement training. Work on getting him back into a set daily routine again. You are a good soul for adopting him. Rescues have the hardest time with change. It will just take some patience and time. Let us know how he is doing and if you need more help.

You might review the sticky at https://www.askmehelpdesk.com/dogs/information-articles-our-dogs-expert-labman-53153.html#post251809

The parts about identifying when he needs to go out including the last paragraph may be the most valuable parts. Where RubyPitbull suggest the same methods as before, doing it the same way may work better for a confused dog than new ways.

In thinking some more about this, while the move likely is part of the problem, it is also a prime age for challenges to your leadership. Neuter him if not already.
The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at Raising Your Dog with the Monks of New Skete (http://www.dogsbestfriend.com/) For more on being top dog, see Establishing and Keeping Alpha Position, Letting your dog know you are the boss (http://www.dogbreedinfo.com./topdogrules.htm)