Hi Steve. Those pesky seams can be a problem! LOL I usually just run the thread between the layers until I get to a point that I can start stitching again. If you need to go a long distance, you can put your needle in an inch or so, pull the needle part way out, then while holding the end of your needle, turn it around between the layers and poke it back out on the eye side of the needle. You can keep doing this all the way across a quilt if you want to and never really come up for air LOL. Although, I can't imagine any reason why someone would need to do that! LOL I'm just saying there isn't any length that's too long for this technique. If it makes you feel better to have stitches even across those seams, then you can do the one stitch at a time thing like mimi suggested. If you don't mind skipping over the seams, just be careful where you bring your needle up on the other side. You should do fine. :)
Also, I agree that family or heirloom quilts should be hand quilted whenever possible. I wish I had more time to devote to my hand work. I still make sure the ones that are really important to me are done that way.