Larry Ribstein addresses the problem of what happens when a partnership gets down to its last member:
The basic problem is that the partnership statutes define a partnership as two or more persons, but don’t specify whether withdrawal of the penultimate partner triggers dissolution of the entity or, instead, a buyout plus continuation by the sole remaining partner.
In my view the answer is clear.
In a two-member partnership, the firm necessarily dissolves and is not continued on dissociation of one of the members because the remaining firm would not have the requisite two members to be a partnership.
Bromberg & Ribstein, §7.03(c), n. 13a. Although you can’t get that from the statute, it is a necessary implication of the definition of partnership.
Larry then elaborates at some length.