CECL - Current Expected Credit Losses

For anyone already planning for CECL, if you are choosing to estimate your losses using the Vintage Method (tracking charge-offs by loan origination year), what are you doing about overdrafts, small lines of credit, credit cards, etc. - evergreen accounts that may have been originated many years ago? Thanks.

We have engaged a 3rd party software company to help us but the general concept they indicated was to pick a "Date 0" if you didn't have solid information to work from. You're early enough that if you start data aggregation now, you should be in good shape having a decent amount of data by the go-live date.