Thank you. External wall insulation would ruin the old cottage look & feel, so that's out of the question unless we're talking single skin extension upgrade, but I haven't even thought about that.
On this note, is it worth investing ~£200 into a thermal camera? Probably on of those phone clip-on jobbies. From what I read online, it's the go-to tool for finding drafts, insulation gaps, tracing roof and pipe leaks and can help check hot electrics. Which seems to cover all of my phase 1.
Toll budget is very tight, but if it saves time and improves result quality, it's worth having.
Also any tips on living in the house that's being renovated are very welcome. Kitchen, one bathroom and one bedroom (will have to be the kids' one for now) are in decent condition to move in, everything else needs to have the interior ripped out.