Try to order from companies that actually bring stuff indoors, or at least with the option to upgrade to "white glove" or "over-the-threshold" delivery. Usually this requires the merchant to sub out the delivery to some kind of logistics company that specializes in this sort of thing and allows for exact date delivery, whereas if its UPS delivering for Amazon they will only leave it on the front door at whatever date ultimately works for them. Some of these companies will hold on to your furniture for you until a specific date, even if that gets pushed back. XPO has been holding on to my Living Spaces order for several months and they haven't charged me any kind of fees, and it is easy to reschedule with them.
If you are ordering random stuff from all over, the best you can do is time the shipments for your arrival and hope for the best. I'd recommend trying to find a mover on Thumbtack to help, and if the person turns out well then maybe you can trust them to drag boxes inside and other set up tasks if anything shows up after you leave. You will also have a mountain of cardboard to dispose of, so you may as well have that person haul that out for you as well.