if you bought the one day 2 park tickets on line, you can exchange them now in case there is a rate increase by the time you go to the park.
i don't know what you paid for your tickets, but you could get the 7 day, 2 park tickets for under $100 at the present time.
you stay on site for one night at uo and get 2 full days of fotl.
check in one night, get the free fotl that day.
check out the next day and use one day of that 7 day pass again and still get that check out day with fotl.
then go back to disney that night when the park at uo closes and you still have your room there to continue that park activities.
so you have 5 days left on your 7 day pass, so what. you have already received your monies worth on the 2 days you have used on it w/ park hopping.
isn't the pound at a better rate now for the dollar?
you might come out ahead if you do the exchange soon.
if you bought on line, you call and tell them the confirmation number of that one day 2 park ticket sell.
you upgrade and pay the difference.
they void out the first tickets you have and send you the 7 day pass, or kiosk pick up for the pass.
i have done that type of transaction before in buying tickets.
if you wait until you arrive, the ticket prices might have increased by then.
that is why i suggest plan on it now.