The best way to know if your current plan can handle your remote work is not to guess. It is to test — not once, but at the times when your work actually happens. Speeds during Sunday morning are often twice what they are on a Wednesday at 3pm when everyone in your neighborhood is on video calls at the same time.
Run a speed test three times: early morning, mid-afternoon during peak work hours, and evening. Note the download, upload, ping, and jitter each time. If your afternoon numbers are significantly worse than the others, you are hitting neighborhood congestion. If jitter is consistently high, your connection has quality issues that a plan upgrade may not fix.
The next step is comparing those real numbers against the actual needs of your job. Two remote workers on simultaneous HD calls need 200 Mbps down and 50 Mbps up as a starting point. Add 25% for background traffic to be safe. For a clean breakdown of what to aim for based on your household and job type, the TestMySpeed guide to best internet speeds for remote workers walks through the math.