In truth, all you need is to blanket the entire of your home, and surrounding chunks with workbenches/wards
If the entirety of the active chunks are unspawnable, then no mobs will spawn.

If you then leave/enter only via portal, no neighbouring chunks will ever be loaded, preventing mobs creeping in with you.
A fortress without walls.

Obviously blocking flying mobs is a little more tedious (especially with the default workbench/ward radius).