The meter in the Nikon F5, like all before and after it, along with those systems employed by Canon, are programmed along the Zone scale and snow should not pose a problem with the F5; it doesn't with the EOS bodies. The meter names are just fancy monikers for dividing the image up into individual luminances then averaging against a predetermined scale or database of several thousand algorithms. If you take the example you have cited, you should aim the camera at an object to either side of the window, lock the reading, then recompose as a test. Then aim the camera straight at the window and observe the result This way you are referring the meter away from the prime illumination of the window to take into account the periphery, where you may want detail. Incident reading of several parts of the scene (shielding the invercone from direct fall-on of light) show the difference. Remember that light coming in through a window will be several stops greater than the ambient light inside and that will be a challenge for most cameras but moreso the limited dynamic range of, for example, reversal film.
I would lean cautiously to a "second opinion" with the experienced used of a separate meter in scenes where you may have doubts what the camera is going to come up with.