The normal way to do this would be to have a collaborator at a US institution invite you for an extended stay. That university could even give you a courtesy appointment like "Visiting Scholar." Your co-author's grant could pay for your travel, accommodation, etc. Presumably you have a specific university in mind, and perhaps even a specific person you'd like to work with, so the next step would be to reach out to them.
An alternative way to get to the US during your sabbatical, with funding for an extended stay, would be to apply to an MSRI program, an IAS program, or some other organization offering a semester-long program with thematic conferences (potentially, ICERM could do something like this but I don't think they currently are).