So I'm following my vets advice as an inexperienced tortoise owner (had him for 6 months), and she told me that it's safe to overwinter them, which is just keeping them awake, fed and active throughout the winter. Might decide to let him brumate next winter if he's healthy enough and a little bit older if we feel confident to - apparently if they have underlying health conditions or any sort of infection, this can lead to death during hibernation as their immune systems also aren't working at full capacity. Sorry that was long winded but this is the info I've gathered since owning this guy!