No the modem is out in the open so to speak by a window. Our house temp stays at 70. I have been watching a lot of Netflix lately, but not while the test was performing. would you suggest upgrading my data?
I'm really not in a position to recommend you upgrade your data or not, that's really up to you.
If it were me, I'd find a way to manage what I had and then only upgrade if it were necessary. Just know that streaming will eat a lot of data, so it's best to try to keep resolutions down to like 360p or so.
Regarding the heat issue, is it possibly dusty where the modem is? If so, might you have some keyboard duster or a vacuum that has the ability to discharge so you could blow out the modem through the ventilation holes? Be careful, though, of course, if you use a vacuum, as that's a lot of force.
It's doubtful that's the problem, as it would need to be a noticeably dusty area for it to be affected in seven months, but you never know.
'by a window' - doubt the sun was beating down on it at no later than 6 in the morning... certainly a puzzle.