Sell HMO with sitting tenants

Other

Has anyone successfully sold a HMO with sitting tenant/s?  I am considering selling mine, and would prefer not to have to evict my longstanding tenants, who have so far not caused me any problems and have  always paid rent on time.  I am aware the property will not achieve market value with sitting tenants, but to an investor landlord, good tenants already in place could be seen as a positive... if I do sell to a buyer who is happy to take on sitting tenants, is there an appropriate notice to issue to the tenants to end their AST with me, or would the buyer's new AST simply override mine on the date of completion?  Thanks.