I am sorry your budgies have to be moved. It is not an ideal situation to say the least.
The cage will need to be safely secured as hawks do and have killed budgies . I have had this happen. They are very strong and can pull a cage over easily. Or get a budgie through the bars.
Your cage needs to be away from drafts or not be out in the open all the time, as it is hot now they will need shade and will feel the heat as they are used to being inside.
Placing the cage on top of crates is not suitable as it is too easily attacked, can you place them with a friend till you are more organised perhaps? Please think the situation through and do the best you can regarding their safety.