I mostly run solo queue. In 259 matches this patch I have won 117 (45.17%), gotten second 80 times (30.89%) and third 62 times (23.94%). Yes, some times I get the team of rouletters and we get smoked. But if you are a good player you should be able to influence close games and have a win rate above 33%, even as a solo queue player.

Premades aren't unstoppable if your team is willing to try. Mark the dark knight commander. Mark the dancer. Tell your team to watch out for them and to purify (guard is useless when that dancer is about to LB) and run away when the they see the DRK diving in. Recognize who the GNB that just wants to damage pad is. Wait for their defensive buffs to be a second away from ending and stun lock them. I've seen a GNB do 3mil+ damage one game, I marked them the next game and kept them to a max of BH2 because I kept CCing them over and over as their buffs dropped off.

Play the map and make correct callouts. Its easy to make a giant comeback on onsal or to make a comeback on shatter because the premade ignores ice completely and only wants to kill. Pay attention to what nodes spawn on onsal or seal rock. Sometimes its better to attack the team in second or third place at the end of games on onsal and seal rock because you can see they are about to get an S rank node for free. Near the end of a game on shatter you have to be willing to pinch through an enemy team's spawn on shatter (or jump from the cliff) if it prevents them from winning with big ice (do not just job with the other team at the normal entrance to their ice, this lets them break the big ice for free).

Again, some games will simply be unwinnable because your team is all rouletters and are just that bad. But most games will be relatively close and you can help influence those outcomes by playing well.