There are a few things you could inquire about to help you both get better sleep:
As my mom’s PSP progressed and she could no longer use the commode independently, she stopped consuming any liquids after dinner and trialed a bladder medication to reduce her incontinence, while wearing comfortable pull ups as a back up. These supports were helpful for a short time, and then my mom agreed to trial an in-dwelling catheter so she could sleep better through the night, with no limit to hydration after dinner which was beneficial. My mom continued with in-dwelling catheters for her remaining years. There are pros and cons with any treatment or strategy, and an in-dwelling silicone catheter was what afforded my mom a better rest. An in-dwelling catheter does require regular replacements (my mom’s Homecare nurse, in Canada, changed her catheter monthly) and careful hygiene practices to avoid/minimize infections. My mom’s GP sent a standing urinalysis order to a neighborhood lab so we could check for infection whenever we suspected this (symptoms can be atypical, like confusion and excessive fatigue versus pain and fever). I hope some of this information will be helpful to you. Please use all medical and Homecare supports available to lighten your load so you can take good care of yourselves.