In their case, the father rented a small studio while keeping their search on for the SFH for the family. This got them the eligibility to apply as a bona fide resident, and kept their rental costs low, and also the kid did not have to move in the midst of the school year.
There may be other ways to solve this but this one worked for them for sure. Hopefully rules have not changed to make this approach impossible -- and hope this helps.
If you are planning on moving here and renting next summer then you could find the place you are going to rent and see if the owner will let you sublet after you register for school. If you are planning on buying then you could look for a place to purchase and rent it out till you get here. Buying a house in Palo Alto is incredibly competitive and if you can buy in Nov or Dec you will have a much easier time than if you buy in the spring. I know it sounds crazy, but many homes are getting 5-10 offers and it can take months to buy a home under 1.5 million. If you move here in the summer and find a place to rent at that time you will be able to register for high school, you just may not be able to get the school you want. If you have a particular preference for Gunn or Paly you will have to have an address in that school's area. But remember, you will get one or the other if you live here so if either is ok then you do not have to do anything until next summer. Both schools are great and the differences have more to do with some of the after school activities than the academics. Gunn has the robotics team, amazing choir, national known theatre. Paly has award winning literary magazine, better sports teams, excellent theatre but not as well known.
Otherwise, it would be best to rent an apartment. You don't want to be cited for defrauding the school.
Feel free to contact me if there is anything I can help you with. Have a great day.