I have mixed feelings about that...

In our zone, annuals love warmer conditions, it's just still too chilly in the garage right now, the night temps are dipping into the 20s. They might survive, but they really won't thrive because it's too cool in the garage, there's no light/sunlight. If you couple that with damp soil (as you have to be careful not to let seedlings dry out), you're also setting yourself up for rot.

Better idea is to gradually harden them off during the daytime. Start out for an hour or two the first day in the shade, then gradually increase each day for a couple days (this will get them used to outdoor temps), then start putting them in the sun for an hour or two a day, gradually increase (this will get them used to the strong sunlight which they're not getting indoors). After about two weeks or so, you'll be able to leave them outside all day in the sun, and that will benefit them in terms of growth (sunlight + heat from sunlight).

BRING THEM IN EVERY NIGHT!!! Frost will zap them. Or you could leave them in the garage overnight but then take them back out in the sunlight when they're at that point.

If it were me, I would leave them in the house about 2-3 more weeks, start the hardening off process beginning of May.