LCA for H1B extension - how soon can employer file it?

My H1B expires on June 30, 2023. My wife is on H4 EAD and due to the long approval time of H4 extension (5+ months)so I would like my employer to file H1B and H4 extension as soon as possible within 6 months. Just wanted to know if the LCA can be filed and approved before the 6 months period as I understand that is a dependency for the I-129 application for extension?

LCA is filed within 6 months of expiry. Due to electronic filing for LCA, it normally doesn’t take long for the approval. You can apply H1B extension in premium and once approved, have the H4 I-94 extended at Mexico or Canada CBP.