A sale does not by itself cancel an ordinary lease. Under Wis. Stat. §704.09(1)–(3), the new owner takes over the landlord’s obligations under the lease. Tenants do not have to leave just because the house sells.
If you want to end an ordinary month-to-month tenancy, the usual rule is written notice at least 28 days before the end of the rental period under Wis. Stat. §704.19(2)–(4). The lease and the reason for ending the tenancy can change what is required, so the 28-day rule is not a move-out date that automatically follows a sale.
For closing, account for the lease, rent, and security-deposit balance. The Wisconsin DATCP Landlord–Tenant Guide’s “Change of Ownership” section also covers the handoff when a rental changes owners: see the March 2026 guide, printed page 12.
Sources: Wisconsin DATCP Landlord–Tenant Guide (March 2026), “Change of Ownership,” printed page 12 and Wisconsin Statutes, chapter 704.