What should i do with my good tenant??

[James Main]

I purchased my first rental property in mid-February. Manufactured home on 3 acres. Hours after closing I signed my tenant. Worked out perfectly and my tenant has been awesome. For example tenant has painted the interior top to bottom, repaired flooring, cleaned carpets, cleared brush, and even installed toilets that I bought. On top of that he has paid rent on time every month during this Covid-19 period. Tenant has increased the value of my property while treating it like his own. 

Tenant is renting for $800/month do to the fact that he is doing so much work around the property. Property should easily rent for around $1100-$1200/month after all the work that has been done. Tenant has a 6 month lease with option for month-to-month after lease is up. He has already expressed the fact that he wants to stay after the 6 months. 

Question is...What should I do at the end of the 6 month lease? I am helping him out with the cheap rent and he is helping me out with all the work that has been done. Do I just tell him "thanks for all the work you did, now rent is $1200/month"? Do i keep rent at $800? Or do I just move on and find another tenant?

I have learned that in the future I will take the time to do necessary repairs before signing a tenant.