Just because the novel ended, does not mean the author Can’t make a sequel.
The author can make a new light novel series that goes past episode 25 and it can be called “toradora 2” or heck the author can even continue the first series and make more light novel volumes (volume 11 and up), never lose faith! I love taiga and toradora, I believe the author will surprise us one of these days with a CANON continuation of the light novel (volume 11 or toradora 2) and that will become a anime and be 25 episodes long
(Light novel 10 is the last novel for toradora currently but that doesn’t mean That volume 11 won’t come, plus the manga still is not finished and they are REALLY taking their time to finish it, so the ending might be different or best case scenario, their will be more content! Material)
Plus the blueray 10th anniversary box set that came out RECENTLY, has pictures drawn by the original people, of ryuji Picking up and holding taiga in his arms at their wedding.
Toradora is extremely popular in 2020, it will come one day. season 2.