It's not like an ODI game. Chasing at speed can be very difficult in a test match.
Going back a bit, but the NZ V Aus game in Brisbane is a good example of why it's difficult to chase. Rain looked like wrecking the game but some sporting declarations made it a game with NZ chasing. They were doing a great job and then to force the draw Australia spread the field (no ODI restriction) and bowled well wide, short or down leg (as they're entitled to do when there's no strict wide guidelines).
Makes it very difficult to chase when the bowlers aren't forced to bowl it into the good hitting zones.
At this point I think a draw remains the most likely option IMO.