On 11/28 I rode from Strasbourg(France) to Basel(Switzerland) by train. Between Mulhouse(last stop in France before Basel) a Swiss "official" came through the train inspecting passports (he could have been customs.) The train proceeded into Basel SNCF and then departed and arrived in Basel SBB--at this point you are in Switzerland, so there would be no more passport checks. The advantage (even with the delay of getting from SNCF to SBB) is that connecting trains (to other points in Switz.) are much closer.
On land transport there will be no passport check in and out of CH in January. Sorry, no stamps within the Schengen area.