@Amy1105 I have a similar internet limitation where I live. There are no phone lines and my internet is cell-based and metered. I try to make it this clear in my listing info- that internet is available but limited- fine to check email and such, but absolutely no streaming, watching videos or movies, uploading or downloading large files. All of my guests have been okay with that. There have been a few that consumed quite a bit because they were doing a lot of online work, but it balanced out with the ones who hardly used it at all.
However, I host in my home and the connection works by tethering to my phone. I turn that connection on when I or guests need to use it, so I'm pretty aware of how long they are online and if I saw that they were indeed ignoring the request not to stream, etc (because I can check how much usage has been consumed) I would just ask them to please not do that.
As well, my place is in the countryside, but not that remote- a 20 minute walk, 5 minute drive to town. All my guests go into town every day, go the beach there, so it's not a problem for them to go to a restaurant or cafe and connect to their unlimited Wifi if they need to. If you are more remote, and guests can't easily get to a place to do that, it would be more problematic.
I suggest you just try to be really clear about the internet limitations in your listing info and reiterate it to guests through messaging when they book. You can spin it as a positive-" Enjoying the tranquility of this remote location means that everything doesn't work here the way it does in an urban center, You'll be surrounded by beautiful nature but do not expect unlimited Wifi- we don't offer that because the capability doesn't exist here." Or "Unplug, unwind. Need a break from the digital world? If you're looking for a place to chill out and relax without being dependent on internet, our place will be perfect for you."
Several of my guests have remarked that they are happy that I don't have unlimited Wifi- they said they spend way too much time online, that's it's addictive, and they were happy to be in a situation where that wasn't possible and just enjoy a quiet vacation.