Have some salt water, at temp, waiting on you at set up, maybe even enough to nearly fill the tank. I have three five gallon buckets of fresh water from Neptune you could use. LMK I am off work Monday and could meet you somewhere. Could even help lift or tote some that day.
I was very lucky all the hoses reached for my one and only move. I changed tanks and did not even think ahead that the sump arrangement would work in the new stand. It did. I also moved so that set up was after most places had closed so there was no way to get supplies on the fly. Would start much earlier next time.
I bought the system from someone and knew I wanted to work on the tank so the fish and rock went in a much smaller tank here to allow me to drill the tank and remove some scratches. No corals to deal with. Moving to the main tank later was much easier. This allowed me to have the empty tank in the space a while before I had to fill it. You have been working on your space so much this may not be needed for you.