Investment Grade STNL. Going Dark or extending lease term?

[Zahid Aziz]

When does an investment grade tenant typically renew their original lease term? 

Lets assume there is a medical property like a dialysis center Davita/Fresenius with 1 year left on the lease and 1 - 5 year option to renew. 

When would the landlord be informed if the tenant will renew or not. Would it be on the last 5th or 6th year. If property with similar lease terms are on market. Is it possible that the current owner knows that the tenant is not planning to renew their lease?