My Scout had glomerulonephritis for years beginning at age 10, but it was evidently more easily managed than Allison's. I've read that there is a rapidly progressive variant of the condition -- perhaps Allison unfortunately has that. Scout did well on enalapril; I'm sorry that Allison hasn't. I also fixed Scout a high calorie diet that was low in phosphorus. Low phosphorus foods can also be high in fat, which later probably contributed to several scary bouts of acute pancreatitis.
Two things you might want to ask your vet about, if you haven't already, are 1) low dosage of aspirin that may help with platelet damage; and 2) azodyl, a bacterial supplement that sometimes helps bring down toxic waste levels.
After Scout began to be incontinent, I bought lots of sturdy pee pads (permanent ones, made for human beds). At first he refused to use them, but gradually I had so many that the floor was covered with them. They absorb a large amount of urine, and you just toss in the washer. He wore washable pajamas all the time, even as the weather got warmer.
Those last few months were bittersweet. Scout enjoyed huge meals even though he was losing weight quickly. He wore a harness so I could help him stand up and go up/down steps. I was sleep deprived from multiple late night potty trips, but it seemed worth it when he obviously enjoyed being out and taking in the night scents. He had a kleenex fetish, and his last few weeks he had a bonanza of used tissues to tear up because I was crying over him every night. He would get up, stagger over to the wastebasket, and start shredding, giving me his patented "Lady, what is your problem?" look when I protested.
I literally waited the one day too late. I had arranged for in-home euthanasia on a Monday, hoping for a last few days together and a gentle death, but Scout had 2 violent seizures on that Sunday, so I took him to the e-vet. Looking back, I wonder if I was holding onto his life more for me, or for him.
Uncertainty is normal at this stage, but disagreement can only make things worse. Sending my best wishes to you, your wife, and Allison.