We are in a very similar situation, a rural bungalow, 2Mbit adsl and insufficient signal of any sort to make a reliable voice call in the house.
Nearly a year ago I used Teamviewer to remotely drive my phone and attached it to an 8m pole and found that at that height I had a usable signal on Three and EE.
I have ended up wit a very DIY/Homebrew solution but it has now been our only connection for over 9 months and works well.
This is my solution
The box contains a POE to 5V converter, Raspberry Pi, E8372 USB/4G Modem, temp sensor and a speed controlled fan.
The 4G mast is at a distance of 7.5km, nearly line of sight, there is just a distant tree in the way, and depending on time of day and weather we get between 20 - 60Mbit. Usually between 25-35Mbit.
I use a SMARTY SIM so put up with CGNAT and Web proxy, but it only cost £18.75 per month.
So it is well worth perusing and as mentioned in other posts there are readily available combined aerial/routers, or homebrew solutions are possible.
I can also vouch for Ubiquiti WiFi, but is certainly is far from cheap.