Thanks so much for the feedback, everyone.
The inaccessible network location on the work server would not apply to me since I'm not connecting to a work server, just my wireless internet at home. I have noticed that the problem is much worse at night, but can't figure out why.
Like Andersson's colleague, I am using a newer macbook pro, but I didn't have this issue the first 6 months of using the upgraded machine. I haven't tried an ethernet cable, it might be a good solution for the time being, but I'd like to find a solution that fully resolves the problem.
Thanks again and I look forward to hearing any further insights.