also, pine shavings aren't the best for a week or so, but I suggest leaving them, and putting down some cardboard and then paper towels for now. Paper towels spread flat gives them better footing for now, but the shavings and cardboard will add insulation as you say. They need real good flat footing for now so they don't get spraddle legged or pull something else by stumbling around in shavings yet. You could add another light with just another 100w bulb to bring up the temp if need be, making sure nothing even remotely flamable comes near either of the bulbs! Honestly, you'll do fine!!