I faced the same setup apart from that the resto druid was a resto shaman and i was kinda clueless even after 4-5 fights. They had the best cordinated burst ive ever seen of any caster teams, they dropped me in the same speed that i drop people with my focus macro.

What ususaly happens is that the rogues open and they focus the char im currently controling, now i was playing with a paladin who used hand of protection wich get pretty much dispelled right away. Anything he trows on me was dispelled by the shaman while the priest was spmming massdispell with bloodlust, if hes lucky he actually manages to dispell my elemental mastery between my 0.5 second shock and lava burst.

One thing i tried was to drop the priest and pop bloodlust, but they dropped my shaman in pretty much the same second. Ive killed the rogue but it didnt help much overall, my healer was able to deal with the damage but killing anything while eating 2x fears + shadow fury and a grounding totem isnt always easy. I didnt even try to kill the warlock and the mage iceblocked always in time, they were both sitting outside purge range and i didnt have enough spellpower to take them down with LvB/CL/FS.

I will def try to go more agressive out against frost mages pets since they are alot of a mages burst and are on a pretty long cooldown, ofc they can use two but it will force them to waste coldsnap on nothing.