How active is your dog at night? My dog gets up several times a night, stretches, and then turns around 3 times before going back to sleep (I call him my Robert Benchley dog*), which would be a problem with a sleeping bag. Certainly any blanket ends up wadded in the corner of the tent! Also, he has a pretty furry coat so a sleeping bag would probably be too warm. I have a lightweight coat (Ruffwear Cloud Chaser) for him to wear on cold nights or if his coat is wet at bedtime. That's in addition to his Gossamer Gear Nightlite Torso Length pad.

A thin-coated dog like a pit bull probably needs a jacket in the daytime, too, if it's cold and/or rainy. It might be that the jacket could double as bedtime wear. My daughter had an Apache River fleece coat for her Viszla (they also have very thin coats, and her dog would start shivering in the mid 50's F). It's heavy fleece and has more belly coverage than most dog jackets. Her dog wore it for sleeping as well as on cold mornings and evenings. You could probably make a similar dog jacket out of a child's fleece jacket, for a lot less money. You probably want a thin rain jacket to put over the top of the fleece when it's raining.

* "A boy can learn a lot from a dog: obedience, loyalty, and the importance of turning around three times before lying down."--Robert Benchley