WI: A Different Missouri Compromise

The Missouri Compromise of 1820 established a dividing line between slave and free states, but it also established states being balanced that held until California in 1850.

What if the balance is the compromise instead of a line?

No state may enter the union, free or slave unless it has a partner of the opposite position.

So first change free and slave states usually entered within a year of each other OTL but unless any of those being pushed forward or back causes a major change the problem will come with Texas/Wisconsin.

Texas(1845) and Wisconsin(1848).

Will Texas wait three years, split into multiple free/slave states, or could Wisconsin(or another free territory) be brought in in 1845?