my god! your one of the lucky ones! There are loads of people out there that would chop their left leg off for a place half the size of that... people who use garden sheds, people who use bedrooms, under the stairs cupboards.. ive seen it all. You genuinely are very lucky

Atleast its brick!. an d its got an apex roof... its massive!

sounds to me; like your on the right track. Persevere with packing the drafts and get a small economical small heater that can be left on all the time... it will soon warm up.