In the US at least, I haven’t heard of a provider not allowing you to bring your own hardware. For example, on Comcast, you can bring your own DOCSIS 3.1 modem that isn’t as full of software and doesn’t allow neighbors to use an Xfinity public network. Comcast even has a page for compatible devices. Save on stupid rental fees.
I keep my house at 55 during the week and 60 on weekends. 51 at night.
Edit: I sleep with a window open even when it’s 10 degrees out and I have a window fan to pull that fresh air in. My wife tolerates it, but I get snuggled more because I run so hot, so it’s a win.