Canadian with American Boyfriend - living in the US

I have an American boyfriend living in SC and we would like to try out my living in SC for say 6 months and them him living in Ontario at my house for 6 months. Both of us trade the stock market for a living, so we can do this anywhere. We trade our own money, so are not employed by anyone.
I have a cat that I would like to travel with me to SC. He has two horses and would like to travel with them.

I have been trying unsuccessfully to navigate the US immigration websites to find out what I have to do to live in the US for this period of time with my cat.
I am aware that I can live in the US for 6 months without giving up my OHIP rights, but I have not actually found the specific website page which says this. The websites are very convoluted!
Does anyone have any specific website pages that I can see? Does anyone see any problems with this arrangement from my perspective or from his perspective?

many thanks in advance.

Which website are you looking for? The one that says you can stay in the US for 6 months, or the one that say you won't lose your OHIP? For the former, check the State Department website, for the latter, check the OHIP website.

Not sure that the horses would be allowed over, check the US Customs & Border Patrol website for information.

You can't work in the US if you're just here as a visitor, not sure if they'd consider what you do a "job" or not. They will certainly ask how do you plan to finance your 6 months in the country, and how is it that you can take 6 months away from your job to do that.