I’ve managed to have restful sleep at 78 with two fans blasting me, plus a window open to let in the relatively cooler night air. It’s doable, but the body takes time to adjust. Humidity can be a big factor.
65 in winter is kind of understandable, since you could layer up or heat a selected space or yourself easier.
My usual comfy indoor ranges would be 70 daytime, 68 night for winter, then 75 throughout in the summer.
Forwards from Grandma energy