I went to TSA, in 2001, after not flying for 10 years. I had the bare mins for the MEL ATP. I did have a LOT of training, plus a number of hours in large (airline-type) simulators, which helped. I got my BFR and IPC, plus some sim training before I went. I never flew there because I passed my sim check on 9.12, and was furloughed a week later...

I have read lately about more pilots going in cold after 10-20 years of not flying, and them having no problems. The current regional training programs, are designed to help people get through with "less" experience than in past decades.

The bottom line is, if you are trainable, and you try hard, it should not be a problem.