Let's see here.
Ryan is an obvious candidate for B2. Apart from Honey G, he's the poorest vocalist left, has been in the bottom before and opened the show during the Strictly crossover. I'll be surprised if he's not in the sing-off, honestly.
As for who joins him there, that's a trickier question. In my mind, Matt and Emily are the only ones 100% safe. Honey G had her weakest performance to date and we're nearing the point where the novelty of joke acts starts to wear thin, so it might be her. Saara could also potentially be in the bottom 2 again, given she sang one of the most boring movie tracks in existence dressed a good decade or two beyond her age. She's also due to come down from her rebound vote. 5AM are the wildcard option, their performance was vocally quite poor and the comments they got were pretty bad as well.
I can't see Ryan surviving against any of these three acts though. They'll use his numerous bottom 2/3 appearances as an excuse to save Honey G over him. Saara would obliterate him vocally and her 3 previous bottom 2/3 appearances don't matter against him as he's been there as many times as she has. 5AM in the bottom would be a shock, which provides the producers an opportunity to engineer a shock exit. However, I see this as a far more likely possibility in a 5AM/Saara or 5AM/Honey G bottom 2 next week.