Insert and Select from Large Table

Good Day

What will be the best way to go to select summary data from a big table with detail records and insert it into another table.

The source table contains approx 100 million detail records for a couple of months. I have a select statement that select a summary of the latest month's data and it average about 15 million records for the month which i want to insert into another table.
In the past i just used a standard insert into statement but not the best way of doing it.

If a view is created with just the last months summary data and i select from the view will the performance be better or will it just add more overhead?

Will a SSIS package work better to insert the summary data?

Any other options?

Thank You