The intersection at Sand Lake and International Drive is always busy. I drive in that area every trip to get from Sweet Tomatoes from the Disney area. It may take a few light changes to get through the intersection, but is no great problem for people with patience. Just give people a break and look out for those who are lost. The entry ramp from Sand Lake onto I-4 can be a mess with people weaving around to find the right lane to get to Disney.
I have found the following to be true:
It will likely be tough to turn north on International from the Wyndham and cross to the left lane to turn west onto Sand Lake Rd. It may be worth a bit more time to exit from the north.
Taking I-4 during rush hour (4-6PM) can be a crap shoot. There can be traffic slowdowns. If you want to avoid the e-way, take Turkey Lake Road to the west down to Disney.
On Saturday night, the exit from I-4 west to the Downtown Disney area can be heavy. Go an exit past 535 for less traffic onto Disney property.
Traffic on Sunday is typically lighter than other days of the week. It is my favorite day to drive from Disney to my favorite restaurants on I-Drive (Sweet Tomatoes, Texas De Brazil, Bahama Breeze).
I have enjoyed many stays at the Wyndham Orlando. If you like salad, I highly recommend a meal at Sweet Tomatoes. Its only about a mile away.
Hope you have a great trip.