There are several options depending on the participants' preferences, but the 'purpose' is probably the most important. If the purpose is 'Easy Fun' then options are limited in this weather.
Changa Manga, if you can arrange the main rest house and the mini-train to pick you up from the rest house and take you to the Mahtabi Jheel and back.
Nandipur head-works(Gujranwala-Sialkot road), you will have to arrange for the rest house and any special permission if required.
For longer trips:
3. Harappa.
Kallar Kahar lake (and/or Katas Temple and/or Khewara Salt Mine) via Motorway.
Mangla dam and Rohtas fort via GT road.