You will get ample number of stay option at Ghangaria. After reaching there you can choose them. Or if you want to stay at free of cost, Gurudwara is also there. In 2019 when we went there, 1 night we stayed at Gurudwara and rest 2 nights at a hotel just opposite to gurudwara. The room charge of the hotel was around Rs. 400 and at that price we got a 4 bedded room. So don't worry.
Being the main season for VOF trekkers and hemkund sahib ji pilgrims, won't room availability be an issue? I have heard of trekking companies book most of the hotels already, which makes it a bit difficult to find stays for those who are on their own. Is it so?