Instead of buying bigger, why not upgrade smaller to bigger.

so apparently when I got around to thinking about the housing, its designed very well and people seem to make more issues out of how the housing system just doesn't cut it.
but for someone hoping to get a bigger plot, they have to go through the process of searching for a bigger plot.
the only problem people should then be facing is to get into the housing.

SE will never do such thing if they do not introduce instanced housing for the simple reason how your client load the zone. This means you will over night get more than double items to load in the zone what will cause massive problems for wast number of players, e.g. almost everyone who doesnt have 2k+EUR worth PC and console players. I'm not 100% sure but i think this is the same reason why SE didnt expand the amount of items you can have in your garden while with Stormblood they double the amount for "in house" items.