My relationship with my inlaws is strained but thats not just because of us moving. Long story.
When we said we are moving my hubby said what he needed to say and my jethani had come over and my mil was all snappy and started saying to her you might aswell hear it aswell and that bella wants to move. I got blamed lol and she didnt speak to me for like 4 days but its like whatever as long as your hubby supports you they wil get over it eventually.
You have the right to live your life and also strike a balance between home and work. Just stress how important it is for work and you have no choice but to live close.
The whole coming into the room and starting to clean up and move thjngs around was annoying for me also. We had our own ensuite yet she felt the need to organise things her way in there and when i tried to say i can manage my own room myself she wouldnt listen i would come back from work and my stuff would be rearranged in the end i started locking my bedroom.
You seem to have a good relationship with them. Dont stress over your sister in laws coming etc thats her daughter at the end of the day and she will always mollycoddle them. Its normal. When my sis in law and kids would clme they would eat sleep drink leave a mess but it was me cleaning up after them so that added more strain.!
Just be prepared for them being upset but they will get over it. Your hubby needs to stress to them its important for your career