We'll just have to respectfully disagree on this point, I'm afraid. If a player is only going to use their house once a month, why even invest so much gil into it, or even own it in the first place? Like with the OP, if someone is going to invest millions of gil into an estate, I would hope that they would use it more than just once a month. Even if it's just a spot to AFK in while they go make dinner or something. I'm still of the frame of mind that if people aren't going to actively use their housing, perhaps they should let those that will have it, and opt for a different housing choice (like an apartment, however underwhelming they may be). And that's not me being bitter that I don't have an estate of my own. I just don't see the point in owning something that you aren't even going to use.
With regards to the end of PS3 support, that was announced months ago, giving people plenty of time to upgrade to PS4, purchase a PS4, or switch over/purchase a PC to play FFXIV on instead. And sure, PSN is notorious for having issues, but I don't think there has ever been an instance where it was unavailable for 45 consecutive days (the most I believe was around 20 days or so back in 2011, which was before this game we play was even released). If something so extreme like that were to occur, considering there is a considerable amount of players on PS4, I would think SE would at least extend a courtesy similar to what they did with the earthquakes in Japan to the entire playerbase.
As for ISP, I would hope that if someone had consecutive internet/connection problems for 30 days or more, that they would consider switching providers. And I don't think computer/PlayStation repairs would take the full 45 days, so that's also a bit of a stretch there. At the very least, if keeping their house was so important, they could probably find an alternative method to logging in to reset the timer (i.e., perhaps going to a friend's house and asking to install FFXIV on said platform of choice in order to log in and reset the timer).
People keep bringing up these individual situations, but I don't think that SE should have to cater to these individual needs. They need to either cater to the playerbase as a whole (like they did when they suspended the demolition timer for EVERYONE), or not at all. Why do so many people want special treatment, and why do they think SE should give it to them? I'm not trying to sound cold or callous, but some of the things listed here would be so isolated in occurrence that it doesn't necessitate changing the system for that reason.
Should housing be readjusted in this game? Absolutely. I'm not saying that the housing system in FFXIV is without flaws. What I'm saying is that some of the reasons listed in this thread just don't hold enough ground to be the reason for that change.