can mean "at least."http://perseus.uchicago.edu/cgi-bin/philologic/getobject.pl?c.20:285.lewisandshort
Roughly: He was trying to figure out where he could find a suitable place for at least clandestine meetings, since he could see that access to adulterous love was more and more being blocked by the large number of guards . . .
The reading of the Medicean ms. "F", dating from the 11th c., is quo nec
, which Helm (3rd ed., Teubner, 1931; there are later editions, but this is the one I have) and Zimmerman (Oxford OCT 2012), following Salmasius, correct to quod nec
is a reading found in later mss., but Helm and Zimmerman apparently prefer the reading of F, with Salmasius' correction, here.