At 82 (last year) we downsized to a 'project' house. 500 years old and nothing, or very little done to it since the early 1970s. Lived in for the last 20 years by a compulsive shopper/hoarder, who did no cleaning or even the simplest repairs.
Why did we do it? well, we are serial house improvers, but this is the biggest project we have taken on. The answer is Location, location, location. We have moved into the centre of a small town, where every amenity(doctor, dentist, optician, podiatrist, 2 supermarkets, library) is within 200 yards, easily accessible on foot or in a buggy and it was the only house we saw that matched our requirements.
One year in and we have had no huge overspend on, admittedly, a very loose budget. Yes, we have had to do things we did not plan for bur we haven't had to do other things we did plan for. We now live close to one AC, and the journey to our other AC and family is far easier and almost halved in length, 2 hours rather than 4.
Our biggest problem has been accepting that we have to pay other people to do things we otherwise would have done ourselves and DH made his health problems worse by trying to do too much, to begin with. Now, after a year of lways having one trades man or another around the house. When we are finally done with them, I will be at a loss with just us in the house.