In reply to chris bedford:
One thing you have to be fairly careful of for the free uplift is checking that it includes coming down, i.e that the date is correct for your down day. If you take down a tent, the campsite will put a date on the ticket, which will normally be the day you are leaving for the route. So you may find you are queried/refused for the descent. Check this and try to persuade the accommodation (the same applies to bunkhouses), to make sure they give a ticket covering your descent day.
You can leave a tent up, but this will cost, even though the Swiss normally give discounts for days when you are on the mountain. With Swiss costs being insane now, every little cost needs to be monitored for most people, and even the cost of empty tent nights is bad news.