When renovating a HDB resale unit that you are staying in, planning to move out or move your stuff to storage depends on the extent of works that you plan to carry out.
The masonry works can be very dusty if you are staying inside. And the furniture can be in the way of the renovation works and get very dirty or even damaged from the works.
Having an option of staying at another place during the renovation would definitely be the best, especially when you are doing works to the whole unit. This can of course also put strain on your finances if the alternative place is a rental.
You can overcome this by having a concrete plan on what you plan to do, how you can break it down into different parts and working closely with your contractor on the best way to execute the plan.
My personal opinion for a whole house revamp of a HDB unit that you are staying in. It will be best to give at least 2 months for the whole process. Stay at another place during the renovation, and put your bulky items into a storage space. This will give the contractors faster access to the place and easier management of the timeline for their works.