Just putting gpsman1's advice in a slightly different way.

The only thing the a/c does for the battery pack is to cool it when it gets too hot. The battery pack is set up to not go above 100F. It's own operation warms it up, so it can exceed that even if the outside temperature is under 100F. Presumably the a/c would have to be cooling the battery all the time if the outside temperature is above 100F.

So whether the a/c is needed to cool the battery pack depends on a combination of what sort of driving you're doing and the outside temperature. If the battery pack needs cooling and the a/c can't provide it, then you lose regeneration and the mileage savings that go with it. You also lose the electrical boost that helps at higher throttle levels. And the engine never shuts down. With partial a/c, these problems would only appear under more demanding circumstances than if the a/c wasn't working at all.

The a/c probably also cools some of the electronic components of the hybrid system, but I don't know enough about that to comment on it.

My a/c system lost all it's refrigerant about a year ago (one of the aluminum a/c lines under the body corroded through). I didn't notice anything until the first hot day of the year (about 85F), when I lost regen, boost, engine stop/start and, obviously, cabin a/c. Replacing the lines cost $1800 plus two trips to the service garage.