You don't really get the benefit of the garden as it stands.
Move utility and WC/boiler to where the kitchen currently is, keep the existing back door.
Create a single story extension with rooflights and big views to the garden on the footprint of the current conservatory/wc area. Not necessarily any whole wall of glass stuff, but French doors at least. You'll need quite an RSJ to hold the back of the house up but builders do this all the time.
Then lay out a really great kitchen and dining area in the space - maybe kitchen in the old dining room, with an island and good low energy lighting to compensate for daylight loss, and a dining table and bit of a sofa area in the extension.
Bargain IMO, welcome to lovely Leicestershire (if you aren't here already!)