There are soooooooooo many variables on your part.....the variables will determine your course of action....
Where in the world do you live?
How long have you had the tortoise in your care/location?
How old/size is the tortoise?
How was the tortoise cared for during winter months before the tort came to you?
I would wait to brumate because you have not had the tort long enough to learn its normal behavior...this established relationship/observation is essential in setting up support of brumation....this additional time will also allow you the time needed to research the various methods that will work for you in your part of the world...it will allow you time to educate yourself and be able to offer a safe set up.
Also, during this time you can be sure to offer lots of food to fatten up the little one as well as get the tort hydrated...some uv time and exercise....keep in mind that the goal when deciding to support brumation is to prep the tort the entire awake months so the sleep months go smoothly.....
Yes, for that age/size of a tortoise it will be fine....just make sure to offer the deepest substrate you can without allowing the tort to stretch and walk right over the top....