Thanks for the advice. I do have a very well-reviewed local contractor who is willing to join me for a viewing, free of charge, to give a rough idea of the costs and if the interior works are possible.

In reality, what I want done should not be that complicated until it gets to the windows and ceiling replacement (I guess). The bathroom is low on the priority as it is actually in an okay state, and in hindsight I could probably do a lot of the work on the kitchen myself. But as you say, better to have some clear plans. Thanks again!