I've never found it a big deal and we have been known to hop around to anywhere from 2 to 4 parks in a day. All on a whim. We don't make any ADRs in advance just day of while walking around the parks and we rarely make FPs any further in advance than the night before. The beauty of hoppers is you can be at MK, decide you want to eat at Epcot so you hop on over there and if you wanted to still see the FWs at MK, hop right back over there. Hoppers make it easier for us to more go with the flow then over planned. I don't know how many are in your party but you might consider the new PH express transportation, it does seem to cut out some time since you skip the security lines and the tapstyles. I've never known Epcot to close any earlier than 9 so it's even possible you could do the HS FWs and hop on over to Epcot and do Illumination. We actually got 3 shows in one night, two weren't on purpose. We were at HS for the Star Wars show and afterwards rode some rides, just so happened the holiday FWs were going off as we were leaving the park so we stopped just outside and watched those, we then walked to BW and hopped on a bus to MK (the bus for MK at HS had the longest line I've ever seen in my entire 30 years of going) and just as the bus was parking, the MK FWs were starting so we stood outside the park and watched those.