This is what we've found works for us when those bills need to be paid when we're traveling.

First, I check prior months' statements to see the due dates. On those which will become due when we're gone, I go online or call the to find out what the current balance is, then either online, by phone or by mail pay that amount plus guestimate what the balance might be on the due date and add some additional dollars to that and pay prior to our departure. If I've overpaid, which is usually the case, it's just credited to my account for the next billing cycle.

Cheers, Rose - Los Angeles