re: Elderly dog barking at night, pacing, and seeming restless - any pet owners with advice?

as others have suggested that would be considered geriatric age for this breed.

that increase in accidents despite a lack of evidence of uti leads me to think that could have been part of a progressing dementia. Perhaps she developed polydypsia as part of the progression and you didnt notice it. This generalized anxiety is common with some forms of dementia.

Im not up and up on the current recommendations for medical management for this. but if the current primary concern is mostly the night time behavior might something to help in keeping her calm at night and sleep. Gabapentin and/or trazadone would be considerations. id ask your vet about it.