The filing date will be the date the return is accepted by the IRS, not the date you submit it to Lacerte.

According to the IRS, MeF for business returns should re-open on Jan 8 (i.e. today).  Have seen other tax products making announcement but haven't seen any from Intuit yet.

https://www.irs.gov/e-file-providers/modernized-e-file-mef-status