I've never tried it myself, but I seem to remember the official brochure offers the option of additional nights without tickets that you can add to the end of your stay. If this is the case, then what you could always do is:
1) Book a 2 nights / 3 day package (including tickets), + 1 extra night without tickets in your first hotel.
2) Book a 2 night / 3 day packager (including tickets) for your second hotel. This should start the day after your sleep your extra night.
i.e.
D1: night 1 of hotel 1 package, day 1 of hotel 1 package tickets
D2: night 2 of hotel 1 of hotel 1 packet, day 2 of hotel 1 package tickets
D3: extra night without tickets, day 3 of hotel 1 package tickets
D4: night 1 of hotel 2 package, day 1 of hotel 2 package tickets
D5: night 2 of hotel 2 package, day 2 of hotel 2 package tickets
D6: last day of hotel 2 package tickets
I'm afraid I can't think of any other way to explain this - I appreciate it might look a bit confusing
I don't know what the cost would be like, but it does mean that you get only 1 set of tickets per day with no duplicates paid for.