This was really hard for us, too (families a plane ride apart). Originally, my ILs (Indian) were going to have some kind of shower/engagement for us in the spring and my mother (not Indian) was going to come to that and meet everyone. Somehow, the lines got crossed and the party ended up being on Christmas Day, the most inconvenient time for my family to travel. Yep, confusing. Anyway, our families are very easy going and, basically, any time I was visiting the ILs, I'd call my mother and she and my husband's mom would chat on the phone. They also exchanged email addresses and wrote to each other pretty regularly leading up to the wedding. It worked out that they only met each other for the first time at our rehearsal. Everything turned out totally OK and they got along famously.