We use our camper all year round at home in the driveway and keep water running as long as possible. We have a septic tank for the house.
Some time ago, when we had the septic tank pumped out, instead of covering it back over with dirt, we installed a neck for the opening that is above ground now with a very easy to remove lid for easy access in the future.
I built a ramp beside it with simple 2x4 and 2x6 supported by 8 inch cinder blocks.
We have a Barker 32 gallon blue tote on 4 wheels. I simply drain the tanks into the tote and then wheel it up the ramp and dump the contents into the septic tank. We're pretty generous with our water at home, including showers in the camper for 2 people. So, when not actually camping on-the-road, we're in the camper at home.
The distance is way too far to dig a separate sewer line leading to the septic tank opening, and would also mean going through 2 different asphalt driveways to do so. So, for us, the Blue Tote works absolutely great!
Because of where we live, I often dump the shower water right on the ground, but the black tank always goes into the septic tank.
You can do the same thing if are on city water-sewer by using a clean-out on your sewer line.