There is a useful website/forum= https://www.ttwebsite.com/forums that should be worth looking through. Sadly all the best accommodation is booked up the year before but here you will get notice of any cancellations for rooms and ferries too. It is worth placing a wanted message on there as well. A lot happens about the end of February when the ferry has to paid for in full. This always triggers the re selling of houses/apartments/rooms etc for those who can’t make it over. It’s a bit of a lottery but my best suggestion is to avoid staying in Douglas if you can. It’s great if you want to live on kebab and chips and like your beer cheap and so cold you can’t taste it, but apart from that…
(theory tested this year) 🙄 I’ll stick with the MGP/Southern100 at least until my Grandson wants to do his first TT.