Off campus room and board 529 plan allowable claim amount

My son lived on campus for the first year and is going to live off campus starting this fall.  The CLA estimate listed on the school website for 2022-2023 is a lot lower than the actual amount charged to us for the school year 2021-2022.  Actual on campus room and board charges vary based on which meal plan you choose and which room in which residence hall that you choose.  There are several different cost listed on the different webpages on his school websites. 

So my question is which amount we can use as his off campus room and board amount to claim for eligible expense in 529 plan ?

1) The actual room and board amount charged to him for the first year he lived on campus even though it was from last year and would be lower than this year, or 

2) The estimate listed on the cost for 2022-2023 admission website, or

3) The actual 2022-2023 meal plan cost (weekday meals only) listed on the school website that off campus students can pick + the cost of a room in a resident hall that has similar unit as the one he will be living off campus, or

4) The actual 2022-2023 meal plan cost listed on the school website that on campus students can pick (there are 3 different plans.  Can we pick the most pricy one?) + the cost of a room in a residence hall that has similar unit as the one he will be living off campus.

 

Thanks for your help in answering my question!