Ive stayed in the annex before. Its lovely. Beautiful views of the lake and its got its own pool and bar and its still only a two minute walk over the bridge to the main pool, restaurant, reception etc.
Its two floors high at the annex, so you could get two rooms on the same floor and then one directly above or below, I think that would be your best bet.
You will love this hotel I am sure. Its so friendly and welcoming, with fantastic staff and stunning views, I could go on forever!!!!