It's really not that hard to get a BG and I hate to put a few hundred $ on the table for a lottery, plus the added time to actually do the ride
I was part of the infamous Jan 2nd IT issues day, everything went wrong and I was able to still get BG 73. We got into the park with 13mins to spare which was cutting it a bit too close, but as long as your in the park you should be good. I'm sure you're reading the BG strategy page and I followed some of the strategies.
4 parks are completely doable as
@AndyR just posted as well. We did just over 10 hours as we did the parade and fireworks. Typically, we do 7-8 hours, but the extra time was needed for both the Parade and Fireworks, in addition to the larger holiday crowds making the FP lines longer. The only 2 rides which had alternate entrances were Buzz Lightyear and Haunted mansion. This was b/c the rides were at full capacity so a 3rd entrance is created for VIP tours to skip the FP lines.