Sweden are into the 1/4 finals, they won all the matches so far. Montenegro had a chance, but they lost probably the crucial match against Croatia and now they have to beat Sweden or hope Hungary to beat Croatia. Germany or Denmark will be the opponent and that match is in the same time. I don'r expect Sweden to waste too much energy against Montenegro because the tournament for them starts after this match.
Montenegro will know their fate earlier - when the match against Sweden will be played, they will know the result they need to go through. If Croatia beats Hungary, Montenegro will try to win and join Sweden in the 1/4 finals. If Croatia won't win, Montenegro will be in the 1/4 finals even with defeat.
The whole championship is without many goals, with strong defenses and good goalkeepers. Maybe Sweden won't push too much in defense, but also in attack. Experiments can be taken in this match. I believe that the lines are slightly higher that the real lines, so I'd bet on under 54-55 goals