Need to figure this out

So kinda in a pickle rn. Currently I haven’t paid for my phone data as I switched my card and my autopay turned off and bill is at $400 rn and my data is turned off so can’t use it unless connected to WiFi, going on vacation next week but don’t really wanna pay for it til after the trip, can I use AT&T go WiFi the portable router it’s $50 at Best Buy will that work and have WiFi the whole trip even tho phone is locked, Don’t care about phone calls only WiFi, and do I need to pay extra after paying the $50?? And if so how much for 5 days