I once owned a "chalet style" semi. the loft insulation was a total joke, the water tank was in fact two tanks either side of the loft hatch so to get through to the rest of the roof all I had was two small triangular holes. I got the council to pay for insulation via a grant so it was fibreglass rolls which I had to somehow shove through these triangles then squeeze myself through.
Being "chalet style" there were flat roofs over the dormer style windows with no way of insulating them unless I made a tool. so I made a thing like a rake with nails sticking out to stick in the insulation and push it out into the thin space above the dormers. It sort of worked but obviously still wasn't very thick.
At one point scrambling through the triangle for the umpteenth time, itching like heck with the fibreglass I got a bit upset and wriggled too hard, busting the ceiling on the triangle, so "making good " had to take place.
No fun at all so I massively symapthise with you, mate!