Ticket options for 2 days (including VB)

[coronationday]

I'm looking to buy Universal tickets for the first weekend of January. The thing is we are visiting for two days, one day for Volcano Bay and another for IOA/US. As far as I know we have two ticket options:

1. Buy the two day, three park, park hopper ticket that would cost over $1,000 for the three of us.
2. Buy one dated ticket for VB and one day dated ticket for IOA/US and that would cost around $850.

My fear is that we buy the second option and, because we are going in January, it gets too cold and they close VB on the day we are visiting and we lose that money and that day. Does anyone know if Universal would be able to switch the dates on those tickets for us if that was the case? Or should we buy the bullet and pay the more expensive tickets and be safe?