I think your choice is sensible. I am also in the Cotswolds 7 km from an exchange and get just 0.8Mb. I installed satellite as well as keeping the ADSL.
I have the same technology Tooway satellite service Avonline offer, but from another seller, Bentley Walker. 20 down, 6 up. If the equipment is accurately aligned (I did it myself) it works OK all the time, but as described above the speed in the day is slow (1-8Mb) and in the evening slower (1-4Mb). But if you use it for downloads at night you get a wonderful service, so you can use Free Download Manager to schedule all downloads to start at 1am, and you can set a Sky box to start downloading catchup TV after 11pm to get the unlimited allowance. So if you can work at night you would be OK.
I'm lucky in that I'm on the Fastershire list for the Gigaclear contract, so if all goes well this summer I get fibre to my house, with a minimum of 50Mb up and down (£40/month). I have opted for 100 up and down, and can upgrade later to 200 up and down or 1Gb up and down. These speeds are not "up to" they are actual speeds (apart from the 1Gb which apparently runs at only 940Mb. So check you are not going to be covered by Gigaclear. The list of 6500 properties is on a spreadsheet you can download here, and it also shows the maps:
http://www.fastershire.com/where-when/phase-two-the-...
These are all digitally deprived properties.