I've left my tank for over two weeks at a time without feeding them on many occasions over the past 7 years and never had a fish die due to starvation in that time. (Only problem I had was one mechanical failure) I've had many different types of fish over the years, including tangs and never once worried about them starving in such a short period of time.
Don't worry about them and don't get anyone in to feed the fish while you are gone. The fish will be fine and other people without experience in keeping fish have a tendency to overfeed the tanks that could cause a lot more problems then it's worth.
A healthy fish will take a long time to starve to death. A couple months isn't long enough for it to starve to death, especially if it can get some supplemental feedings either through copepods that were once in the tank or the occasional bit of frozen foods it can pick up. In a tank that small chances are it will take about 6-8 months to show serious signs of malnutrition and stress. If you really want to know how "Happy" it is in a small tank like that, ask him again in a years time how well it's doing. I'll place my money on it being dead in that time!
Fish are NOT like humans. Many of them can live a very long time without food (there are always exceptions like Anthias and tangs that need constant feeding however even a few days is nothing to them really) before they show signs of malnutrition. This is because of their relatively low need for energy production. A bottom dwelling fish such as mandarins don't need to expend energy to keep them neutrally buoyant as they simply rest on the ground when not in motion. Most fish rely on their surroundings to regulate their body temperatures and metabolism so they don't waste energy on extra heat production. Fish are very well suited for locomotion in their native habitats and have generally developed in such a way as to minimize the resistance that swimming through water takes such as secreting a slim for water to flow past them very easily and a body form that reduces water resistance. The main things that fish use the majority of their energy for is growing and reproduction. This conservation of energy adds up to their ability to go long periods of time without eating or having to tap into their fat reserves. However mammals are used to feeling the effects of not eating within hours due to our need to produce and consume energy in our own bodies and we tend to erroneously transpose these needs onto our fish.