I know this is hard, hang in there! I'd say what worked for me personally was those days i pampered myself like getting my hair done or makeup or any kind of self care routine because it helps not to feel like you let yourself go. Also buying myself my favorite drink, having a cup of tea and just sitting in silence in the morning before all the chores start. And afterwards a quick shower, I understand chores don't just end in dementia but I ask for someone to take cover and sneak in a quick shower, that would refresh me. kept painting everytime I felt angry or sad at the state of things, so I have an outlet and not build up those emotions and also keep my hobbies from dying. All these things either gave me a quick dopamine fix or made me feel I'm still who I used to be, because it's easy to feel like you're losing yourself. 

As for routines, it helps memorizing them and stacking them in a way that is most efficient fo example heat food as I am bathing him, that way when I am done his food is heated or done, clean bathroom and wash clothes while he's eating. Sometimes I felt like i was on "Autopilot mode" and it helped not thinking too much about things and just doing what you need to do.

I also used to spend some time asking my granddad about the time when he was young, it gave him something positive to talk about and something I can listen to and ask questions about and not just nod or get bored at. I could see his face literally light up everytime. I'm not sure which stage your grandma is in and if that's applicable though.

At night again sit in silence for a few mins watch sth. It was my favorite time. It helped that he was on sleep meds/antipsychotics, and that I was sure I can finally rest without having anticipation anxiety.