I managed to forget spare trousers when packing to come to my mum's and only realised when I chucked my dirty clothes in the washing machine. I managed 4 teeshirts, plenty of underwear, 2 jumpers, scarves in case it was chilly and only 1 pair of trousers which I had on.
Thankfully my mum is a similar size so I found some of her leggings as she was out. The washing machine had a fast spin and I banged my jeans in the tumble drier for 20 mins cos I Do Not have the physical spoons to do outside laundry (which involves either carrying stuff the long way round or fighting with broken doors that I can't open). That's self care innit.