@jog18
With my son watching my laptop connected to the receiver and listening on the phone, I took the transmitter for a ride on the luggage-rack of my push-bike.
The receiver didn't miss a beat going through three of my neighbours' houses at 250 metres from my laptop, on the crest of a gently rising and falling ridge (like yours).
As soon as I started going down the other side of the ridge, NOTHING AT ALL.
Maybe it's possible with special aerials or amplifiers, I don't know.
I saw srnet's reply just before I posted, but posted anyway because you asked me a question.
You can buy LoRa modules for less than 2€ so I'd take his advice and give it a go.
Good luck!