Chris pretty much already does all the things needed to live independently: he pays the bills, he gets food and toiletries, he can drive wherever he needs to get to. It's not like he's going to suddenly forget how McDonald's works and starve to death in his bedroom. Hell, if he got rid of the hoard, I bet he can even cook simple meals for himself.
The biggest issue is going to be his shopping habits. He already spends ridiculous amounts of money on stupid shit, and when Barb dies he might start buying even more to try to ease his grief. That will be mitigated by losing Barb's pension/SSI and having less money, but I'm betting Chris won't get it at first and will have at least a few issues with missed payments before he finally gets it.