As it is, unless you really push yourself to keep playing, you'll probably be 'done' with a run by two seasons, three seasons at most. By then you would've unlocked everything you can with your current playstyle, not to mention that currently almost all the seasonal events are centered around Autumn and the starting parts of Winter. I don't think there are any proper events that take place in the later half of Winter, Spring and Summer just yet (I don't count Valentines' as I think only Eden has an event at all for it).
Not only that, I feel like the game would require a few more low Warmth outfits before tackling Summer, seeing as with the current temperature system, you'll overheat if outdoors at 30C, even if completely naked. Maybe Vrelnir would have to implement a sort of 'clothing air-ability' to outfits counter the heat, or maybe just wing it by having a hand-held air fan or something to deal with Summer (lest the player be stuck constantly hiding indoors to avoid the heat, as realistic as that maybe ).