i would choose 1dc because they are so durable and very reliable, also the customer service with canon is great so if the unlikely event of something going wrong happens there probably is someone to fix it not far away. With the sony its also more work to get the great look of the 1dc.
What country are you going to? If there's lots of rain and very cold outside the a7sii wont enojy it whilst the 1dc can handle it like a champ.