I work full time, as does my wife, granted I can be very flexible with my hours (self employed) and when my two were pups i was able to take them to work in the back of my pick up and check on them regularly. I live in Lake District too (UK) in a rural area and my dogs don't actually get to be on their leads too much tbh. We manage to get out on shoots about twice a week, sometimes even 3, 4 days a week and that's an all day affair so I'm confident that their exercise requirements are met. I realise that not everyone can accommodate that kind of exercise regime and I sometimes think that maybe I've over-exercised them after a possibly strenuous week, but hey-ho "a tired vizsla is a happy vizsla" so they say.
I'm not sure I'd be happy about leaving a pup on it's own for up to 4 hours, could be kinda stressful and maybe give it some anxiety issues that may arise into adulthood. That said though, my two are fine left home alone for about 8 hours a day no problem while we're at work.
"never argue with stupid people, they may drag you down to their level and then beat you with experience"..Mark Twain
Ruby's d.o.b. 21/6/2011,,Lyharr Grouse Shot d.ob. 7/01/2015