Do you actually need a closer ratio gear set ( as what 11 speed is, because both 10 speed and 11 speed has the same range min to max cogs) on a folding bike.

Or maybe because the newer range of 105s are 11 speed. My suggestion is to just hunt for the older 10 speed 105s. Or get the Tiagras. In Shimano usual cases, when they upgrade or improve on Dura Ace, the older Dura Ace technology will become Ultegra and the Ultegra then will become 105s. This means the present 105s are actually the older Ultegras. Which also means the 2015 Tiagras are actually the older 105s.
The wheelset is not the point actually. The hubs are! For 11 speed, you need an 11 speed compatible hub. Easiest way I see is to get 11 speed compatible hub but sadly, folding bike spoke numbers are different from road bikes which are usually 32. So maybe you can hunt for 20/28 hole hubs which are 11 speed compatible. ( Try Taobao ) If you can find a pair, then you can just change the rear hubs or together with the front as well, your wish. But bear in mind, Tern/Dahon front hubs are only 73mm wide as opposed to the usual 100mm for others. The increase in 2.8mm width for the hubs can actually be absorbed by the frame with no problems.
All this means, you will change to drop bars or bull horn bars, right? I haven't seen an 11 speed straight bar shifters locally yet. The SHIMANO SL-RS700 is available for 11 speed and the price is going to be shocking too!

I think you can order 11 speed wheelsets from Taobao, you need to troll through their site and if you do order make sure you get the spacers too, in case you need to go back to 10 speed.
Or why don't you visit Kimbell Jaya and speak to Jimmy. He has quite a number of 451 and 406 wheelsets. Maybe, he can modify them with 11 speed compatible free hubs. I can't guarantee but it's worth a try.
My conclusion , I will stick to 10 speed as the improvement in performance between 11 speed and 10 speed is negligible in the case of folding bikes.

listen to sifu.
If you converted to 11 speed, you'll be wondering where your money's gone. A lot of things are actually wasted on a foldy. Sure your gearshifts may be a tad smoother, but seriously..... Blindfolded you won't be able to tell the difference in feel from Tiagra to Ultegra.