You should retain NJ counsel to get a local perspective on this. However, in general if the expenses are ordinary and necessary, they should be reimbursable. Unless someone is arguing that you are traveling on their dime, it should be fine. Talk to a local estate planner to get specific.
I recommend that you reask this question but the next time set your location to New Jersey. That way, a New Jersey lawyer will be able to properly answer your question.
Disclaimer: This answer is provided for informational purposes only, does not constitute legal advice, and does not create an attorney-client relationship. Actual legal advice can only be provided after completing a comprehensive consultation in which all of the relevant facts are discussed and reviewed.
As my learned colleague suggests, this needs to be asked of a New Jersey lawyer. To answer it, the lawyer will need to learn whether you are named in a Will as the executor or whether you are appointed in an intestate estate, and the lawyer may need to see the Will. You might, however, get the answer yourself by calling the Surrogates Court in the appropriate county in New Jersey. The probate clerks tend to be quite helpful in the counties I've seen, and they are used to dealing with pro se executors.
Reading an answer on the Internet does not create an attorney-client relationship. You are represented by me when we have both signed a retainer agreement (on paper or electronically) and some money has changed hands. Usually, you will have been asked specific questions about your situation and all potential conflicts of interest will have been resolved. Until then, you have no more right to rely on this answer than if you read it in a novel.