An upright freezer looks like a refrigerator and moves like one. The tall, narrow shape makes it top-heavy and tippy, so defrost it completely and keep it firmly strapped and upright the whole way.
Pro tip: If the freezer is a manual-defrost model, it may have far more ice than you expect, so start early.
Watch out: An upright freezer is top-heavy and tips easily. Strap it to the dolly and use a spotter on stairs and ramps.