I have no familiarity at all with the area you're hiking in, so I may be way, way off base here. However, based on what others have said, I have to wonder if the MSR Hubba series tents might work for you. As far as the idea of 2 tents, you could contact them to see if you could buy a Hubba HP from a retailer, then order a "replacement" Hubba inner tent. I think the same fly works with both, and you'd get the advantage of the all-mesh interior in summer. The pair might cost you about what a 4-season tent would. Just a thought - no idea if it's workable.