Retirement takes a lot of adjusting on both sides. I do believe it is easier if both have always had independent interests, hobbies, activities- and neither expects to be 'velcroed' to the other 24/7.
Having said that, and taking on your concerns- life is really just too short to be working full time at 70. DH is the same age, worked full on and very long hours till 63- then retired from one day to the next- and has never looked back. He does not expect me to the there all the time- as I've never been- always been very active and working too- so it is 'normal' for us.
Whatever you do, do NOT downsize now, at least not too much- having space makes a big difference. Bonne chance, we will have a chat about this soon.