Depending on what arrangements have already been made, it might be necessary to conform to, or arrange for exception to, local/state rules in the US. Unfortunately the rules can be exceedingly vague, variable, and arbitrary, even from one town to the next one down the road, and may not necessarily be what one would wish to have done.

Most people in the US rely almost entirely on Funeral/Mortuary services for the whole process, and providers of those services are generally as well informed as they need to be; but if unusual transportation of the remains is expected, or likely, it probably would be advisable to inform anyone from whom you intend to obtain any services of the full range of what you might want before agreeing to have them start anything.

From the way the original question was stated, it would appear that things have already passed the point where that's a consideration - but just in case ....

John