Well it depends on what he has as a load... If he has a 200a service for the sake of having a 200a, he may have a load demand that is far less. But it has all the bells and whistles and 100 amps of general lighting, and two 60a AC units - then no.
But the options of an essential and non-essential panel or larger gennie is a common method of doing it, and he should be informed of the options. Either way you get what you pay for. A few thousand more for seperation of the whole works, or simular amount of money more for a 30-50kW. Which the latter is enough to power him fully and a neighbor or two maybe? Depending on equipment loads? The only time I have ever seen a 200a service pull 200a is at X-mas during a catered party w/ 20kw in lights and caterers on hot plates.... I just questioned the size because powering 50A of an available 200 sounded odd. Often a service of that size will be that size due to something large as a load....
