I've had a couple of headliner experiences, including with my CE. Except for duct tape, DIY fixes tend to be very temporary. Usually headliners come down for a reason. The back pillar covers are pretty temperamental, so removing those with the hope of putting the headliner back in order and putting the covers up is a little more difficult than it would seem. I'd recommend just getting it looked at early, and maybe they can save it, rather than needing a new headliner in short order.
I bought an excellent new headliner for the CE, which, according to the upholsterer who put it in, fit perfectly. I got it at World Upholstery,
www.worlduph.com