Mine always seem to go stale within a day.
Depends on the kind. Soft bread freezes really well, so when I make burger buns or sandwich loaves I always make extra and freeze them as soon as they cool. I thaw at room temperature the day I want to use them. Crusty bread can be revived by sticking it under a running faucet and then putting the wet loaf into the oven for a few minutes. I usually do it at 350°F but I don’t know how long. I just check frequently.
I’m making these for my partners lunch sandwiches. He doesn’t have access to an oven.
He could try warming them up in the morning before leaving and putting them in a paper bag instead of plastic. Fresh baked bread keeps the crusty texture well in something breathable (like paper bags) but I’m not sure how the reheated ones would hold up.
Shortly after baking, when they have cooled down most, but not all, of the way, stick them in a plastic bag. There are even some white loaves that require this step to get really good texture. An example from Food Geek.