Christmas caroling accompaniments are available for free download from http://www.gbod.org. Save to disk or drive, take the “piano” with you.

From that link:

These piano accompaniments of familiar hymns are provided as free downloads as a joint project of The General Board of Discipleship and United Methodist Communications. They are intended to provide accompaniments for congregational singing for those churches which, for whatever reason, are unable to provide accompaniment for singing. You may find that you can also use them for choir, solo, or Sunday School use, Christmas caroling, or singing at any group setting. All accompaniments are provided without copyright. You may use them for any purpose without charge or having to seek permission.

In almost all cases, we have provided accompaniments from The United Methodist Hymnal (1989), with an introduction and multiple stanzas in the key provided in the hymnal. Occasionally an alternate harmonization is included. Watch for new hymns to be added in the future.

Also most of the Methodist Hymnal is available as sheet music (I guess that term is now defunct!) for the iPad. The app plays each hymn, as well.