I'd call this a renovation, not just a refurbishment! It depends if its just cosmetic, or if any structure work is required though? If its needing re-wiring etc though, this will cause a huge amount of mess potential to expose structural issues which might also need sorting.
We have just done similar, but 1930's, detached, 4 bed, more bathrooms and SE. We started at the end of covid and material costs have gone up dramatically. Ours needed a new roof, all new windows/doors, new plumbing, new boiler, ground work, new kitchen, bathrooms, re-building of an old extension, the additional of a small, double story extension, new double garage and more. We are over £250,000 so far. Structure work is done, but 'bits' are left such as bathroom cabinets, spare bedroom furniture, in-built wardrobes etc.
We lived in a static caravan on-site for the first 2 yrs. Neither of us are in in trades, but did what bits we could. Yes, its been a labour of love and we still aren't finished. We love the area, the neighbours are great and its our forever home. If we'd planned to flip it, we wouldn't make our money back.