This is what our 17 yr old ASD daughter does given half a chance. She is in a safe place and doesn’t need to interact with people in the real world.
We have worked hard to inject reality into our daughter’s life and now she functions pretty well with a bit of exercise, social interaction and fresh air, though will always need a certain amount of time alone to decompress.
We found the only way of doing this was by refusing to leave her alone until she did something (eg an hour of fresh air sitting in the garden). Gradually we have established routines which now seem set in stone (advantages of autism) and she will do without encouragement.
At the weekend her day looks something like this
11.30 get up, get phone
at some point go out for an hour
at some point have some lunch in the kitchen
6pm family meal
8pm play with younger siblings
9pm join us for tv, her choice of programme. Leaves phone downstairs for night.
As you can see we don’t insist on much and where possible she does what she wants. If this routine needs to be changed eg for an outing she needs to know several days in advance. Outings are obligatory (eg a family birthday) or optional.
Writing it down makes it sound horrendous for a 17 yr old, but routine is the key. She now gets enjoyment from activities we nagged her to do (eg tv together) and with the safety of these routines feels able to branch out a bit sometimes, and now suggests outings.
No idea how to get her to keep room tidy. Pick your battles, gradually install routines involving some social interaction and some exercise.
Good luck x