I would bring the pot into the garage and water it when the soil feels dry to the touch or about once a week to once every two weeks. You can bring outside about two weeks after your average date of last frost.

I've been watering every week or two, but its on my porch, no room in the garage.

I might wrap the sides of the pot in bubble wrap (which you can cover with something for aesthetics if so desired) to minimize temperature swings. The plant should be fully hardy in a sheltered spot in a pot in your zone, but by keeping the soil temperature even, it will be less stressful to the plant and should decrease the likelihood of early leaf-out if you have a brief mid- to late-winter warm spell. Without being sheltered by large volumes of soil like in-ground plants, the soil in a pot tends to freeze and thaw repeatedly over the winter, which isn't particularly good for the plant. Hence the suggestion for insulation.

The goal would be to have the soil lightly moist, not dry and not soggy. How often the watering is needed depends on how dry the air is, what the temperature is, etc., so you really have to establish how moist the soil is by sticking your finger into the soil a few inches. IME H. paniculata cultivars like Little Lime really don't like wet soil, so you want to avoid that.

Thanks both of you!

The soil is very well draining, so I'll try to keep it slightly moist and hope for the best!

Will knock on wood. Knock, knock, knock!

With no indication of where you are, your likelihood of success can't be predicted, a1an. In my well drained soil and really cold zone, few things survive in a pot regardless of pot size or insulation. I bury the whole pot in the loose soil of the veggie garden and then mulch over it, and that gives me the best success.