Christmas hates modems

[#1]

So the tree goes up, the lights go on and the modem gets funky.
I'm trying to find a solution that will allow the Xmas tree lights to be on and still reliably access the Internet. I'm working through some options and it would really good if I could access the modem stats in real-time so that I can experiment a bit.
Currently, I have a ping test running full-time so that I can watch for drop-outs in the router, but I'd much rather monitor the modem. Is it possible?
Cheers,
Extra fibre, typically 70/20M, standard modem and router

[#2]

The modem can be unlocked, if you're feeling technically competent at that.
Otherwise a TBB BQM (aka ThinkBroadband Ping Graph) can be helpful. It is a ping test that works in towards the router, and presents you with reasonable graphs. See the sticky post at the top of the forum for commentary on these (the 2nd post has links to a collection of other Plusnet users).
The graphs then help show packet loss (as a thin red band across the top) and disconnections (as red spikes) - both of which you may get from Christmas lights.
It requires a static IP, but you could use one temporarily without a static IP, for short investigations.
Alternatively, but some different lights with a better power supply!