This was way easy and you might not need the extra hose.
I added a hose spigot and 10 feet of hose to the plumbing on the curb side of the RV, by just adding a "T" fitting to the water line that feeds the rest of the RV, that was inside the same compartment that has my winterizing hose attachment, but after the pump and check valve (opposite side of the pump that has the winterizing valve and ultimately comes from the tank). I wanted this cause I wanted an outside shower on this side of the trailer to clean the dog rather than the one that was already there on the driver side in the utilities bay usually used to clean out the stinky slinky.
Now all I have to do is turn the winterizing valve that shifts the water from drawing from the tank to now be drawing from the winterizing hose and put that hose into the portable water container and turn on the existing pump. Now my whole RV can be fed pressure this way right out of the portable container, and all I do is run the hose that I added and put it right into the water fill cap that is also right near by and let it fill the tank. This hose also lets me fill the tank from city pressure without unhooking the city hose from the RV.
It would be the same as using the winterizing valve found on most RV's that are used to draw antifreeze into the RV's plumbing system through the pump, but then just using the outdoor shower hose to fill the tank, except I added another outdoor shower to the curb side of my RV to make things easier.
My tank will only gravity fill so this is my way of getting water up to the fill without lifting anything, and I don't need an extra pump