Insulating old (1790s ) house - conflicting opinions

[Jumpy Guy]

This might sound over simplistic, but could I "half insulate" it, and add a vapour barrier.

By that I mean thinner insulation than I'd like, allowing some heat to escape into the solid wall.

Vapour barrier to prevent moisture.

In practical terms, 2" of celotex rather than 4" ?

I completely understand that no one can tell me it's the 'right' solution....

[Olivera]

Is the property currently acceptably warm and is mould/damp free? If so I would add nothing at all.

[Jumpy Guy]

I live in Scotland, on the edge of a moor, so it would always be nice to be a bit warmer...