Have my 5Ghz cake and eat my 2.4 too?

I draw on an iPad and mirror the screen with to a larger display with apple TV. This works well on a 5Ghz airport express network, even at trade shows where cell phone interpherence makes Wifi spotty, however I'd also like to have some internet access on my iPad via my Verizon 4G jetpack. I've tried extending the mifi network but the Apple express doesn't want to cooperate. I'd buy a wifi iPad if it would help but am guessing it can't juggle more than one ball in the air.

Can I have both?

BTW the closest I've come is by having a macbook air on hand that shares the mifi network via bluetooth WAN, but that is extra baggage and seemed unreliable.