Remote exhaust is a lot harder than you think. That engine is running hard, the exhaust is hot. Not very warm, really hot. It's not uncommon to see the muffler glowing red hot (hard to see in daylight). This isn't like your mechanic that has a rubber hose over the cars tail pipe while he is working on it. An engine running at idle in a shop is way cooler than one under load. And being you want to keep it mobile, making something that can be detached makes it even more difficult.
Next is the heat. Inside a 2-car garage. Some quick back of the gray matter math shows me you will be dumping about 20,000 Btu of heat load into the garage not counting exhaust heat since I figure you need to get that outside anyway. That is a lot of heat, probably perfect for heating an uninsulated 2-car garage in Minnesota during a polar vortex.
So the answer will still be the same. No, you will not be running this inside your garage. You will be rolling it outside into fresh air and run it in your driveway just like you would in a remote location. Except the neighbors will be annoyed.