Ise Jingu on New Year’s Day

My family will be visiting Japan during New Year's and would like to visit Ise Jingu on New Year's day. Will trains and the shrine be too crowded or is it reasonable to try a visit from Tokyo?

What is "too crowded" to you?

Ise Shrine is among the most popular shrines in the nation for hatsumode, so it will of course be crowded, but isn't that the reason you chose Ise Shrine for New Years? For the special experience?

If you just want to visit Ise Shrine because you have interest in the shrine, then New Years may not be a good time, but if your purpose is hatsumode then I think it's a good choice. There will be crowds but it's not as if you will be unable to get on the trains. You can go if you want.

Here is a picture of the crowds at the main shrine in Naiku with information about hatsumode at Ise Shrine (in the "Local Customs" section):
http://members.virtualtourist.com/m/a40e1/ee43c/

I visited Ise Jingu (Naiku) on New Year's Day this year (2013). The crowds are there but not unbearable. Expect about an hour's queue up to the shrine altar? where folks throw money and make their prayers for New Year's, slightly faster if you are okay with accessing the altar via the side door rather than under the main Torii gate.

Okage Yokocho eateries will be extremely crowded but there are many stalls selling foods along the streets with taiko performances and the lively atmosphere makes a fantastic Japanese New Year's experience.

I remember I had to take a later train back to Osaka where I was staying as I did not make a seat reservation in advance and the afternoon trains were all full but that only gave me more time to check out the area.

Overall you can expect major crowds but Japanese are quite patient and orderly and the crowds should not pose much of an issue. Just practise a little patience and you will be fine.

Hope the above helps.