I really think that it's both inaccurate and unhelpful to keep using the term 'inevitable'.
Because it is inevitable. You cannot completely avoid the heat, or cold passing the through the insulation.
Which it simply doesn't in the UK.
It absolutely does - a few days of it being too warm outdoors, and we get threads, exactly like the present one.
Then you also seem to be ignoring the cold of winter, making homes cold.
Both due to the ambient outdoor temperatures, making it's way through the insulation.

