Went up to Maya lake last week, just felt like we needed to get out of Calangute for a few hours. To be honest it's not worth the journey. The lake was quite nice but there wasn't much there, the boats were not in use and the small stalls around the roadsides overlooking the lake were closed. We found one restaurant open but the table cloths were absolutely filthy and it made me wonder how filthy the kitchen must be???
Have a drive up to Dona Paula it's much nicer. Lovely scenery around that area, boats for hire a few market stalls (selling mostly clothes) and a couple of little restaurants. You might want to avoid Sundays because it's really packed. You can pop into the Cidade de Goa on the way for a drink in the hotel bar overlooking the sea. On the way back pop into Cafe coffee day on the Miramar Road, take a walk around the park or have a look around the outdoor art centre place.
GFF xx