I'm lucky in that I'm near Salisbury plain, so can canter there, although have to box to some of the better bits. There are usually a couple of decent tracks in the woods, some are too soft except in the height of summer, and others are fine in the winter but solid in the summer. I'm also hacking distance to some gallops, although I have to use a fairly busy road.
The flip side to that is that my horses are an hour away from home!
I feel almost guilty posting. In the densely populated mid Surrey area I'm spoiled for choice with bridleways and BOATs. There is always somewhere to canter, even when frozen there are areas under tree cover with leaf mould. Only problems are huge increase in walkers, cyclists etc due to furlough and WFH and difficult to trailer anywhere, there are so many issues with illegal traveller camps in the area that almost all the car parks have height bars on them. But minor issues compared to what some on here have to contend with.
The school where I ride has fantastic hacking - lots of bridleways you can canter on (some lovely long canters) and a common where you can gallop at certain points. Needs some road work to get to the best spots.
We're limited too, in the local area anyway. There are so many gates that it's hard to get a decent canter for more than a couple of hundred metres max. There are some better tracks in the woods but to get to those you need to hack for a few miles including along a fast windy road. Plenty of stubble fields but we can't ride on them. I got so fed up with it I bought a trailer to box out for the odd longer / faster ride. In theory our hacking should be amazing but day to day it's actually a bit frustrating. Although I shouldn't complain, I have friends whose only hacking is up the lane then back down the lane.