Ordnance Survey are your friend here - the government agency that does the mapping and has divided the country in to areas for sale as maps - used by hilllwalkers, ramblers and anyone going out the front door before the age of the smartphone.
Go direct to their site or elsewhere on line and buy their map OL45: The Cotswolds - Burford, Cirencester, Chipping Campden and Stow on the Wold. You may be losing a bit round (some of) the edges, but that's the one.
The best paper map is probably the Ordnance Survey Map OL45 at 2 1/2 inches to the mile
shows all roads and footpaths and places of interest
This covers most of the northern part but not south west
One problem with it is is double sided so OK to use on a table but not too easy to use the reverse side out on the road
there are other OS Maps at various scales
There is really only one quality map for the UK and that is Ordnance Survey.
If you want an idea of their quality, Bing Maps has the OS 1:50,000 and 1:25:000 mapping online - same as the physical maps.
Bing Maps used to haev the option of showing OS maps - it's not showing for me today. Either theyv'e stopped, or for some reason Bing doesn't want me to see them.
You can still browse the OS maps at streetmap.co.uk though, in s a slightlier clunkier way.
While researching, bing.co.uk/maps on a desktop has the OS map in the layer dropdown. It won't show on a mobile.
Once in the UK you can buy either paper or waterproof maps from any outdoor store, though you'll have best luck in the area around the Cotswolds. Stores include Cotswolds, Ellis Brigham, Blacks, GoOutdoors, plus independents. In London there is a fantastic map store called Stanfords.
If you have plenty of time to wait for delivery, blacks and dash4it are the cheapest retailers.
You can buy them on Amazon.Edited: 11 October 2018, 18:17
When buying a paper OS map these days you also get a code so you can download an electronic version on to a phone or computer