Tried this game solo and it seems to work quite well .
Remove 30 tiles.
Refill = same as 2 player game (remove a tile from the common pool).
Fight= instead of putting the fight token, take 1 food point.
Fire=instead of putting the bear token, take 1 shelter point.
All the rest stays the same. Try to beat your best score.
Current score after 3 plays: 22.
Have fun !