If it’s habitable then I’d just move in and live in it as it is until you’ve saved enough to do a decent amount of work. Living in a building site is worse than living in a house that needs updating, I think. Although obviously that depends on how bad it is to begin with.
We bought our house in a habitable but in need of renovation state. We had a starting renovation budget of £50K which quickly disappeared into new windows and repointing one wall. Then Dh took a 50% pay cut, so all renovation work simply stopped for a few years till we’d got back to being in a position to afford to carry on.
Six years after moving in, we were finally able to get on with it. Still couldn’t afford to do the whole project all at once so our builders suggested going top down, a floor at a time (we have three storeys) even though the kitchen was the most desperate.
I’m so glad we did that! The first year we did the top floor, so after that we had a lovely master bedroom suite and office to retreat to. Having the roof sorted gave peace of mind and the new skylights over the stairwell flooded the whole house with light which gave everything a lift.
We then had a welcome few months break from builders and dust until the new financial year, when we did the second floor. Kids and guest accommodation sorted.
Another break, and now the third year of renovation sees us finally, FINALLY, tackling the desperate kitchen and the main living areas. All the dust and mess is confined to the ground floor; we can escape upstairs to the rest of the house to get away.
Doing it this way has meant that accidental pipe leaks, builders foot through floor incident etc have not damaged work already done, and having fully completed areas has made a three year renovation less painful that it would have been doing it piecemeal. Saving up and then spreading the cost over three years made it financially manageable too.