I think they'd happily spend a few hundred quid on flights if they thought it would pay off ratings-wise. The main reason I think he won't go back in is that they did "their side" on Aftersun last night, and there's no way he'd deviate from his and Jess's version of events after that even though they were both totes lying. As Mike is hotbutboring there would be little chance of drama:
Dom: "You completely mugged me orf, can't believe you did that, fuckin' muggy-"
Mike: "We didn't sleep together."
Dom: "Oh right. Sound."
Jonny better not frig Camilla over, although I thought it was suss that they rekindled things after the first couple dumping and he genuinely thought they were going to be in the bottom 3. I would guess that Dom was giving it stacks about him not being into Camilla as he knows people have little loyalty to Tyla, and also he's made it clear he's not into her and is gutted Jess left. So they would be an easy choice to make if you were having a hard time picking a couple to dump.