Hi Readyout,
Welcome to the Heartland Owners Forum.
The plant is closed until after the holidays so you may not get an answer here.
On most models, the inverter output is dedicated to the residential refrigerator, but I have heard that on a few models, Heartland has also used it to provide power to a nearby outlet or two.
If you look in your front compartment, which is probably where the inverter is located, you may be able to spot the model number and look up the output rating spec on the manufacturers website.
If you have a 22 cu. ft. Frigidaire refrigerator, it very likely draws close to 1000 watts when the compressor starts. If Heartland used a 1000 watt inverter on your coach (as they have used on other models), that extra outlet might not be very useful when you're running on battery power. But when on shore power, that outlet would still probably have around 800 watts available if it's powered through a 15 amp circuit breaker. More if it's a 20 amp breaker.