The current situation is probably about as good as it gets unless they release even more plots and outright remove the need for players to log on within a certain amount of time in order to keep their plots.

It's really hard to draw any fair lines when it comes to rules on housing. How do you decide how much effort is enough for retaining ownership? How do you decide what the proper length of away time is? It'd be so much better if we just increased the amount of plots and made the time you could spend away before your house got demolished more forgiving. FFXIV is supposed to be one of the best games out there for respecting a player's time but the housing system doesn't reflect that right now.