The dinner at Norway is such a special treat that I would reschedule the dinner rather than risk not making it. Chances of afternoon thunderstorms in the MCO area are quite high in September at 4 PM, and if you get delayed even a half-hour, you're going to be hard-pressed to make that dinner. You don't say whether you're flying non-stop or connecting, and if it's a connecting flight that presents additional opportunities for things to go wrong with the timing.
As Katie said above, Uber has some vehicles (in several classes) equipped with car seats. But that program is apparently being phased out, and not many cars still have car seats. I just checked MCO and there was only ONE UberX vehicle available with a car seat there. X with a car seat to BC would be about $45.
If you need more room than X, you will need to take Uber BlackSUV with a car seat (+/- $80), and there were none of those available when I checked.