probably no
So, probably no.
You could certainly put an airport express in your cabin and use that for additional authentication, but you're probably just better off connecting your iphone to the network, doing the authentication on the iphone and having the AW connect as usual to the iphone over BTLE.
The AW sadly cannot do http credentialed authentication or authorizations. It can do SSID UN/PW credentials as it gets that direct from the iphone, but having to authenticated the login and confirm anything it just won't do.
I had to ask my gym for them to create a username and pw for me to login to their network in order for my watch to work while my phone was in the locker.