Mycelium is a phone only wallet. So if there is no wireless network, you can't use it. Blockchain is a web wallet, so you could use it on a computer if there is no wireless network and you get a wired network.
By the way, there are little devices called nano router or travel router or pocket router that can open Wi-Fi from a wired Internet connection. Prices are roughly around $20, and my current recommendation is the TP-LINK TL-WR710N 150Mbps Wireless N Mini Pocket Router, Repeater, Client, 2 LAN Ports, USB Port for Charging and Storage, see
http://www.amazon.com/dp/B00FRMAOIO . It doubles as an access point, a repeater (extender), and as a direct ISP router.
No, I don't work for the company, but I have one of those and like it. The little device is astoundingly capable.