I have a similar (worse) problem. Have to rely on "weak-link" for wifi and
1.5Mbps is only on a perfect day. Usually less than 1.0 and nothing at all if a rainstorm that gets into the wires. Our local technician is great but there is only so much he can do. For a zoom meeting, I can participate on a good day but download is not clear and I use audio only on the upload.
One partial solution is to make more use of my iPhone and cellular data. The cellular data is not great but in many parts of the house can be up to 5 Mbps on a good day. I was able to get a low cost unlimited data plan and can either use my iPhone. I have very limited hotspot ability to allow my computer to use the cellular data through the phone. For a relatively high additional charge you can get higher speed from the hotspot.
Next step, when it is time to replace the laptop, I will get a tablet instead and for a small monthly charge, I can have the tablet as an extra line and use cellular data with the tablet. My current unlimited plan is limited to two lines but by time I am ready, I Verizon may change the rules.
One other benefit of the unlimited data is that if I want to download a basketball game when they restart, I can go to a part of the house with good cell coverage and download to the phone. I can then move it to the computer. A game downloads to the phone in about 15 minutes. A download directly to the computer takes up to 8 hours. I have to do it at night with less traffic on the internet and even at that it frequently fails and I have to start over. That was a big benefit of getting the unlimited cell data.