It's really the EPCOT fireworks that are best seen from Topolino's but I think in December those are actually later ... they shift from the usual 9pm to 9:30 pm to accommodate the last performance of the Candlelight Processional for the day. But yes, you can have a leisurely dinner or if you feel like you're trying too hard to space it out, can always just go to the lounge. For that matter you could explore the resort for a bit and then return to the lounge. It's not like California Grill where you have to be let into the elevator or need a receipt to be able to return. As others said, you'd probably want to go out to the terrace to view anyway unless you happened to have one of the tables by the window.