As it turned out she was still miserable and having frequent urgency and peeing around this softer foley catheter all night when I had her back home (good times). Next day, got her in for a consult with Dr. Aguirre, expecting to be told there was not much left for her, and was surprised to find out that the part of the tumor which was blocking her from peeing was mostly growing into and not attached to the urethra (though it had encroached at one point near the bladder). It was like a finger extending from the bladder into the urethra with a lot of blood clots to boot. Last Friday she had the surgery to unbock her and she had a bit of a bumpy recovery, but got through it and is getting back to her old self now.
There is still tumor in there, but this has both bought her time and also made her more comfortable, which I consider a win, win, except for my credit card balance.
Had the emergency vet got the foley in the first night, I may not have made the call a couple days later when she was out of options, and found out about Dr. Aguirre. Dr. Aguirre is a great vet who was able to save Sunny's bacon one more time. After discussing her case I found out that he has a lot of experience working on tumors and kidney stones for dogs, and applies some techniques used in human surgery for similar problems he deals with in dogs and cats. It is not often that I have met a vet at his level, and of course, I would highly recommend him.
Superpisser is not out of the woods yet, but she is in a much better place to find her way out.