Different players are going to have a different idea of what an adequate amount of time is to have to take as a break from the game without losing a house.
It's rather weird, but right now the demo timer lines up well with the schedule for the content releases (outside of the somewhat longer period between .55 and .0). As an example, x.1 patch is released. Player subs, plays the content for a few weeks then goes to play other things. They just need to remember to log in and enter their house by the day their current game time runs out. Now they have a solid month they can be unsubscribed before the x.15 patch is released with more content. They resubscribe for x.15, again play for a few weeks (remembering again to log in to reset demo timer as their game time runs out) then can unsubscribe the following 5-6 weeks at which point x.2 gets released. It doesn't work for those looking for extended breaks but it works well for those who just want the break between content releases.
As for easily fix the situation, I agree they can fix the situation. I don't agree that it would be easy for them to do in the time/cost sense.
Adding a better instanced housing system would be the best route as it would be a long term solution and they already have the bare bones basis for an instanced solution via apartments. What they need to do is to expand it into larger spaces with a variety of backdrop elements (and those spaces do not need to be the size of Island Sanctuary). Players could enter their instances homes through the wards just as we currently enter our apartments through them. Still it would take time to get these elements developed and test before they're implemented.
If they intend to stick only with the ward system being the only source of houses, they then would have to make long term plans in advance. Adding more wards would mean adding more physical servers to host those wards, and that means the physical data centers they use would need to have the additional space available for them before the need occurs. Physical data center juggling hasn't exactly been a strong suit for SE with the player base getting upset for various reasons (location choice affecting ping depending on where players live on a continent, the ATT/NTT node issue dispute recently, etc.)
But definitely I would like to see SE fix housing one way or another so the availability/demolition drama can go away. It's an annoyance that doesn't do the game experience any favors.
Except this isn't true. You can purchase another FC house if you already have a FC house on the same world as long as the account character that originally purchased the first house is no longer in that specific FC. If you're trying to get a second FC house on a different world, there's nothing in your way at all outside of standard get the FC set up and wait out the 30 days.
You could even purchase 2 or more FC houses on the same world in the same lottery period (if you get lucky enough to win that many) by purchasing one house for the first FC, removing the purchasing character from that FC then purchasing the second house with the other winning character. The only thing you would have to avoid doing is using a FC Master character to purchase the first house if there is no other 30 day+ member on your service account in the FC to transfer Master to.
If SE was trying to hinder multiple house ownership under the current system, they did a very poor job of thinking out how players would likely workaround the restriction. It adds in some inconvenience but it's not an obstacle. The hardest part is setting up the FC in the first place (since a second service account is needed whether it's your own or that of a different cooperating player) then waiting out the 30 days for lottery eligibility. Rank 6 is far too easy to achieve now with the current amount of Company credits generated by Expert Deliveries.