It's been a long long time for me, but back in my bar band days (late 60s-early 70s) we had two keys players in the band. We carried a full size upright piano and a Hammond D.
When I still lived in Muscle Shoals, I used to drive my gear up to Nashville to work at the old "House of Gold" studio. The only access was up three stories by way of a narrow, rickety metal fire escape.