Sam and Dean....

I don't know they would probably be to busy lying to each other or fixing another apocalyptic mess they caused themselves.😀

As this movie shows, even with meticulous planning and safeguards in place the mirror is nigh-on-impossible to beat. I don't know if Sam and Dean's usual method of blundering in and figuring it out as they go would have worked, but they might have pulled it off through sheer ballsy luck. I mean, they've beaten an evil mirror ghost before, but the way they did it was kind of ludicrous and made no sense.

Of course, they're both carrying way more emotional baggage than the Russell kids were, so the mirror would have had a field day with them.

Nah, pretty sure Sam and Dean would have had a fight about something stupid and uninteresting.