www.camping-sursee.ch is a site we have stayed at a couple off times going to italy,they are happy to let you stop one night which is hard to find in switzerland.The site has clean facilities and is only 5 mins from autoroute. You need to book early as all nationalities stop there. Worth a stay.
If you have`nt been through the Gottard tunnel beforewe have found that it is busy throughout the day and as it is a constant uphill climb both ways it was best to go through at night.If you want any more info happy to help