Indeed, as Allan laid out it is rare to see high levels of conversion with cold email marketing BUT I'd argue that is primarily due to our approach.We instinctively think, as @Keegan Van Kooten outlined above, that we should lead with us (who we are, what we can do for them, etc). 

A legal mother/daughter conversion. 2 separate entrances, 2 kitchen, etc. 

I'm assuming that's how I should think of calculating it, but I'm not certain on the conversion rate I should expect.He would also be living in the home and I would purely be operating as an investor.

The opportunities will present themselves, you just need to be available to participate in those conversations.

I would dive deeper into the conversation and see what you can make happen that way you can have a better plan. 

I'm looking to chat with someone about options I can throw out to the seller and how to have the conversation with the owner in general.

I messaged maybe 20 people, ended up having real conversations with about 8-10 and the one I booked ended up coming back to me after these conversations. 

The right conversation just has to be had. 

As an Investor-Agent myself, I have had several conversations on this topic with my clients and customers.

When you have the conversation - Have a discussion to see what the tax would be on an outright sale.You may have suspended passive losses that would eat up most of your gain.If the property was previously a personal residence, there may be some exclusion.If you do have a gain upon sale, have a conversation to see what options(if any) you have of deferring the gain and what the steps would be.