We missed you too man!

The problem with games and performance really is that you have a limited performance budget. If you aim for 60 FPS, your performance budget is 16.6 ms. How you spend that, well, that is up to you and your games requirement. So it's really hard to guess what a WED setting would look like for tablets. Would it be so that it eats up all of your performance budget? Would it be the absolute minimum before looking like shit? The problem is that the map is just some part of your game, and how much of the performance budget you are willing to allocate for it, really is up to you.

PS: Get real hardware! I did the same mistake, build an iPad app without having an iPad at hand, just testing it on my computer. Worst. Idea. Ever. The actual experience on an iPad is so so much different than whatever you simulate and I can't stress enough just how important real hardware to test on is. Sell it on ebay afterwards if you don't need it afterwards anymore.

Edit: I know this probably isn't what you want to hear, but if you are serious about the project, that's the way to go.