From what I've seen (from the host's side) a lot depends on the company/institution. For example, our university has a dedicated international office, that can take care of a lot of the admin.

In smaller companies, this is usually the job of the office manager, so it's a bit less predictable whether they will have the bandwidth.

Depending on the city, the biggest issue is going to be housing. Expect to pay a lot and expect the host not to be able to help out.