Unless the wifi router has a built-in capability to monitor load capacities, your best bet would be to contact your ISP and see if they have a means of testing bandwidth usage over time.

If the router is more than 3-4 years old I suggest replacing it.

In any event, The Linkcyst is about at $100 router when new and more to the point, recurrent yet intermittent failures are the siren sound of failing routers.

The higher performance consumer product lines are the upper end Netgear, SonicWall and lower end industrial Cisco routers. Note that the good quality Cisco routers do not include the Linkcyst/Cisco branded editions. I use mostly the Sonicwall TZ series and a variety of Cisco routers at my customer's offices. The Cisco Aironet 3800 series is a new edition nice and fairly inexpensive enterprise class tool.

__________________
Toyota is a leader only because their drivers block everyone behind them. Oh what a feeling.