I'm reminded of how there was an "Insulate Britain" campaign group, using unpopular disruptive tactics; the outcome of that was the law changed and they got jailed for several years, and the British public could go back to not thinking about insulation again.
There isn't much space inside for insulation, one solution is thin wall insulation.
https://assets.publishing.service.gov.uk/government/uploads/...
The solution would be to knock the house down and build a modern one on the reclaimed land. But you've just bought a mid-terrace, so that's out of the question.
Yeah. One of those complex issues that just keeps getting worse as you dig into it. I think people in the UK are much more conservative about historical preservation of ordinary houses, due to both percieved ugliness and build quality issues and also some genuine regressions of utility from, say, the days of the Parker-Morris standards.