Well, no, it will not blow Visionaire Studio. In "Zak between time & space" or in "The Whispered World" we got huge animations, too. There are no limits...
Generally: If the animations are larger than the memory space this could slow down the game because the animations have to be loaded from the hard disc (which is slower than the memory ram). But this is a problem AGS, WM AND Visionaire have.
And please rethink if such big animations are necessary.

My game will be in 1280x1024, main character sprite is 512 pixels height, he has loooong idle animation (and some other stuffs too): about 10 seconds (10 or 15 frames per sec), will this blow up the engine? Or is doesn't matter how long the animation is because the frames will be loaded continously from HD?