The size, variety and splendour of Monty's garden is staggering at times as with Carols too, but he's also been there +20 years and Carol has been at Glebe cottage +30 yrs. In all that time, soil improvement, landscaping and establishing plants have been key to their successes. Knowing their plot has helped them to understand what works and what doesn't. And one of the reasons I truly enjoy Monty's presentation on GW, is that he shares his failures too. If he's not some gardening genius who never gets it wrong, then I have hope that I may achieve something similar in my own garden.
Draw inspiration from the GW programs and tailor what they're doing to knowledge of your own plot. I live in Kent and yes things grow here in the summer, but that doesn't mean I don't meet challenges or watch some programs with very little relevance to my own garden. I've yet to add water, so the pond episode the other week was completely out of touch with me, yet I enjoyed it all the same, learning something along the way and enjoying the success of Monty's hard work that was shown last night. It doesn't mean I'm going straight off to dig a dirty great big pond in my garden, it wouldn't fit, but when the time comes for water, I can draw inspiration from what I saw.
As a side note, perhaps you are expecting too much from your veg if you grow them without protection so far north? I know not everyone can afford polytunnels but I'm not even bothering with outdoor tomatoes or peppers anymore and I live in the far south! blight gets mine every year!