Tell us more about your idea. Why would we need a second farm? How would this work?
I mean the map of the valley can be expanded i guess. And transportation is available. Its like home farm, pelican town, the beach, the dessert, the mountains and some additional farm lands which can be purchased as a secondary farm. Maybe the other types of farmland (riverland, hilltop, etc) can be incorporated in only one saved game. No options will be made in the beginning of the game. Standard farm can be the default farm in the game and the other types of farm will just be included in the map, and the player therefore, can expand and buy those lands during late game. Just an idea :)