I have not tested this, but you can try heating from frozen - double your cook time to about 60 minutes - bake covered for the first 30 minutes, and then uncovered for the last 30 minutes.
For low-carb/keto, leave off the breadcrumb layer either on a portion or all of it. Use a low-carb pasta or marinara sauce to keep the carb count low. Serve over low-carb pasta, riced cauliflower, or just savor it straight up if you prefer!
Nutrition information provided as an estimate only.