I have friends that I don't get to see very often and it can be very difficult. part of me really wants to be friends and enjoy the memories when we are together, but another part of me doesn't even want to make them because it can make the distance harder. I think that its really important to soak up the good times though! Make the memories with your work friends while your with them so you can reflect back on them later. Maybe consider planning another reunion with them so you have something to look forward to after they leave