I can describe some general tips for protecting tender plants from cold temperatures.

Depending on how large they are, you can attempt to cover them with lightweight fabric (a light sheet) or clear plastic film. Unless you are going to arrange a frame over the plants, I would stick to the lightweight fabric. I use Agribon in my garden for a little protection.

Thirty-three degrees isn't terribly cold (it's still above freezing), and a lot of tender plants can tolerate a short cold period as long as it doesn't linger long enough to freeze. Covering the plant will insulate slightly and keep it ~1 to 3 degrees warmer during a brief temperature dip.

I think you can leave them in the ground, especially if warmer weather is just on the other side. Nurse them through any short cold spells, and they will enjoy the remaining good weather.