The temperature rise will be depend on how vigorous the fermentation is, and on the volume and shape of the vessel you ferment in. You'll see a temperature rise of about 5-10 degrees on the homebrew scale, in my experience. Still, it varies widely.
I would suggest getting one of the thermometer strips available at your local homebrew shops. They are reasonably accurate, and they're an easy way to monitor the actual fermentation temperature. And they're cheap.
If you find that your temperature is too far off, there are some cheap and effective ways of controlling temperature, up and down. For example, if you find that your temperature is too cold, you can use an aquarium heater to warm it a bit. If you find that your fermentation is too warm, you can use the "swamp cooler" method by wrapping the fermentor in a wet towel or cloth and putting a fan on it, or put it in an ice bath in your bathtub.
All of that said, if there aren't drastic swings in temperature (such as might result from strong drafts or being near a heating vent), then your 65-degree basement will likely give you a good, not-too-hot fermentation. Still, I would get a thermometer so that you can monitor it.