Question: Wouldn't the city have found out that someone was using the hotel when there was electricity being used but no-one to pay for it?
Question: One of the dogs, Chelsea, has only three legs when they find her the first time; obviously she can't run or walk very far, so how did she get back to the at the end of the movie? She wasn't in the van when they were taking the dogs back and the only dog that was left behind was the one that Bernie saw, and Chelsea was there when Bernie was calling out some of the dogs by their names, so where did she come from?
Answer: Lots of people were running with the dogs to the hotel so someone could have very easily helped Chelsea get to the hotel the easiest way to get her there would be to carry her.
Answer: Not until there's a 3 month period where the electricity usage is much higher than normal. Even then, it takes another few months to get it noticed, and another couple of months to send someone out to investigate it.
rswarrior