(2) Whenever nonconformity or default with respect to one or more deliveries substantially impairs the value of the installment lease contract as a whole there is a default with respect to the whole. However, the aggrieved party reinstates the installment lease contract as a whole if the aggrieved party accepts a nonconforming delivery without seasonably notifying of cancellation or brings an action with respect only to past deliveries or demands performance as to future deliveries. [1989 c.676 §57]