Well, with Dandeer out of the picture, Dandelor could instead turn his efforts to neutralizing her mind control spell. Which would, after a fashion, address the 2v3 Super Saiyan issue. That said, I'm not entirely sure how we plan to reach Dandeer or Vegeta around Berra - Instant Transmission has a visible gesture that takes time to execute, and I'm not sure our speed advantage is enough to give us time for it.
If we use Instant Transmission, though, he can't sense whether we're going for Dandeer or Vegeta, which means that he might prepare to protect the wrong one, and since Golden Oozaru is slower than we are, if he's protecting Vegeta we can then go for Dandeer instead. I'm also not sure if Golden Oozaru Berra can even DO anything if we Instant Transmit next to Dandeer or Vegeta in a way that he'll have to shoot through them to get at us. Non-Oozaru Berra could deal with this by using Instant Transmission himself, but I don't think Oozaru Berra is fast enough to counter our Instant Transmission with another.
..Also, just realized that you were afraid of Berra preventing us from using Instant Transmission in the first place rather than antipicating it, in which case I'm pretty sure it doesn't take longer than a punch and/or a ki blast (Goku used sucessfully Instant Transmission in his fight with Cell, who was faster than he was, for once).
So, something like this, maybe?
[] Write-in: Fight on. You can still win this.
-[] Try to get around your father and take down Vegeta before he returns to base form. If you can even the numbers, you can still salvage this.
--[] Try to Instant Transmit next to Vegeta so that he will be between you and Berra.
---[] If Berra intercepts you, try to turn it into a feint and immediately go for Dandeer instead.
Hopefully Instant Transmitting would make Berra focus on a possible attack on Dandeer rather than Vegeta, and even if not, having Vegeta as a meatshield between us should prevent Berra from simply aiming a blast where he predicts we're going to Instant Transmit.
Of course, there's the risk Berra might simply attack through Vegeta to get to us (though I don't think that's likely), and I'm also afraid that adding a contingency about going for Dandeer might make the initial attack on Vegeta less likely to succeed in the first place due to Kakara's attention being split.
The whole using Vegeta as a possible meatshield might also be unnecessary detail in the first place and prevent Kakara from flying if that's the most efficient way of getting Vegeta, though I don't think that's likely either.
We could also just try to do a feint (pretend to attack Vegeta, then go for Dandeer) in the first place, but then I'm afraid that Berra might see through it.