Don't worry, I can help! I've been there, it's stressful but SO worth it!
We live in Georgia, most of our family was located in Pennsylvania, and we got married at
Castaway Cay on a
Disney cruise! We had a reception in Pennsylvania to celebrate with those who couldn't join us on the cruise. : ) My main piece of advice is, if you have a budget to stick to, keep things as budget friendly on the Utah wedding as you can. The closer you get to your Disney wedding there will be little things that pop up here and there you may want and you don't want that money tied up elsewhere if the Disney wedding is more important to you. For example, I had my cousin who has a nice camera photograph our at home reception to help cut costs because those pictures weren't nearly as important to me as the Disney ones. One thing I recommend to keep you from getting overwhelmed is plan certain days of the week to set aside planning your Disney wedding and other days to set aside planning your at home reception. I did Mondays and Wednesdays were my "Disney Days" and Tuesdays and Thursdays were my "reception days" I set a rule for myself that I wouldn't even think about the other wedding that day unless I absolutely had to speak with a vendor or something. It helped balance a lot. Plus, this way I usually had wedding-free weekends to simply enjoy being engaged! : D
Also, I suggest making yourself a wedding timeline. Plan what you want to have done by when, and take everything one step at a time! Plan the more fun things like registering for gifts and your bridal shower (if applicable) during more stressful periods in the planning process, such as right around your signing date and about 2 months out to help give you something wedding related that's FUN to do during the most stressful periods. I would buy two separate binders, and organize one for each wedding.
As far as budget, Etsy and eBay may very well become your best friends. Remember, you're only going to use a lot of this stuff once, so don't shell out a ton, and buy used wherever you can! Plus, by going on Etsy you can get very unique things such as homemade photo albums and guestbooks and invites. Rent whatever you can as well. We rented our Cinderella's carriage birdcage to hold wedding cards at our reception and it was perfect! (After all, what would we have done with it afterwards?)
Finally, and this is something I already touched on, but my main thing I would change if I could do it over again is not spending as much on the at-home reception. It was lovely but there were a few things I shelled out for (such as a pricier venue, because I didn't want it to look thrown together, or expensive custom invites) that I would have rather had the money for little extras at Disney or for our honeymoon at Disneyland. I hope this helps you and feel free to PM me with additional questions (or just support!) : D Enjoy this wonderful time in your life!
