IMHO, the whole point of the game is to engage in combat with some opponents. Killing HQ, flying off the map, these are things that seem to run counter to the point of the game. More to the topic, though, I'm ok with large maps. But truth be told, when the population is low and you have to search to find a fight on a large map, I don't think the real problem is the map.
(Also there should be extra candy out on the table when one country falls below 50-60%, imho. Like B-29's with a single atomic bomb that could level a field and town. How cool would that be.)