Pilsner froze into slushy whilst lagering...Need more yeast?

So, I've got a Czech pilsner lagering. brewed with Wyeast 2001 Urquell yeast. After approx 3 weeks lagering at 32 degrees, I decided to wind it down a little further to 28.5 (-2 celsius). I guess my temp probe needs a little calibration, as upon checking my keg, it sounded very 'dull'. Inspection reveals it has formed ice slushy'ness throughout the beer, but not frozen solid. I can still pull beer from the out post.
It's currently thawing, before going back into the now 32 degree fridge. It has another 2 weeks lagering before I'm filtering and racking to a serving keg for force carbonation.
Opinions on adding fresh yeast at this stage? I krausened with fresh yeast when racking to the lagering keg. I know some yeast will still be alive and well, and will go to work (albeit very slowly) when it thaws. Is it worth buying another smack pack, activating it, and dumping it in?

Thanks!

 

the yeast should be fine. really no need to lager below freezing temps. let it warm and thaw

 

Thanks Yooper, Bellybuster. Will do. I'll let it thaw, and then business as usual. Thanks for the replies