This is not exactly a home security problem, but i thought you guys might be able to help me out: So my parents own a farm where they need to be able to see when the cows are calving. At night they don’t always want to get up and check if the cows are calving which is why they wanted to set up cameras to be able to check from the house. So the barn is about 50m away from your house and there is no wifi-connection over there.

Here is where i need your help:

I could install a LTE security camera and solve the problem that way, the problem being that paying a subscription for the camera system to work and the internet-provider is not exactly the idea (the cameras would only be in use for about 4 months per year).
I’ve seen these cool “Nano Beam” stations from Ubiquiti that would connect these cameras to the house through directional beam technology, and since there is a free line of sight to the barn this could be usable (the window of free line of sight is not very big so idk how that would affect the connection).
So, would it even be possible/feasible to send live footage over these Nano Beams to the house and somehow be able to check it on the phone or should I go with a LTE security camera solution?
Which mid-range camera system would you recommend for this low light scenario in the barn at night?

(sorry for the long message)