Even if Iceland had tied the game today I think they wouldn't be able to get a point vs Croatia in the final group stage match day. They would have ended up with 2 points total. And Argentina are going to rain hell on Nigeria in the decisive 3rd game. I think Messi and co. will beat the Super Eagles with a big goal difference at that. It's a matter of life and death for them at this point.
Interesting... Will they make it happen? I think so , Argentina would get into next stage dramatically... Beat Nigeria for 2-0 only , that's enough for them to secure the second position of group D with 4 points and goal difference of -1 where Nigeria -2 . That's the scenario would happen later , I'm pretty sure about this. A crazy last game of group D !! Make your bet on Argentina, huge odds there.
Yes there is still opportunity for Argentina to advance to the next round. If and only if, Argentina were able to qualify for the round of 16, I consider supporting them for the rest of their game. Remember Portugal on EURO 2016? They had a bad start but they were able to win the event. Maybe the pattern will be repeated by Argentina in this world cup.