waiting for a Shiny
oh well no Shiny yet but have amassed 3200+ candy and a host of Gyars
3070 CP 100% B/HP
3062 CP 98% DT/HP
3032 CP 89% DT/HP
2332 CP 96% DT/C
2223 CP 89% B/HP
2140 CP 93% DT/HP
1679 CP 96% B/O
1535 CP 93% B/HP
Have another 7 Karp that are 91% - 93% and levels 16 to 30.........dust is not a problem yet as have 1.86m....
Answers
If you already have some good ice types for fighting Dragonites, then you can probably start comfortably with transfering the B/O.
I would not have powered up the 89% D/H, but no reason to transfer it now.
The 2223 B/H and 2140 D/H, for me, would be on the chopping block. Not worth the dust to power up, not likely to be usable at their current size. I suppose 2223 B/H might be usable if you are forced to use higher CP mons to prestige because of a Blissey at the bottom of a gym.
The 1535 B/H could probably work occasionally for prestige against really high Rhydons.
Wait until the end of the event and if you do not get anything better at a higher starting CP, then max out the 96% D/C.