My view is that statistically one is just as likely to have a suitable field(s) nearby, as far away.
So there isn't much point in aiming to glide absolutely as far as possible. Obviously one wants to maximise time in the air to check obvious things (fuel tank change, carb heat perhaps) but I bet most real engine en-route failures cannot be restarted, and to make a mayday call and set 7700.
As it is a lot easier to control the glide in azimuth (left to right) than it is to guess where one will end up in terms of gliding range (especially given wind shear) I would pick a direction, into wind if possible, where there is a number of fields lined-up on one's track. Then if you miss one field, you can go into the one behind it.
Anybody should be able to do this, even without practice. Doing an accurate forced landing into a specific field requires a lot of practice, and if it is for real, one will be doing this stuff under a LOT of pressure. Just think how some ATCO with a personality problem, or a passenger being sick, or kids fighting in the back, can spook you into making mistakes, and multiply that 10 times for a real forced landing.