In general, when upgrading electrical service for a single family home from 100 to 200A, does the feeder need to be upgraded, or is it just the service panel?
The service entrance conductors are sized to your main breaker in most cases. The drop or supply to the meter is any ones guess I have seen them large enough for a 200 amp service on an 65-75 amp panel but we did have to up size the service entrance conductors from the meter to the new panel. In some cases due to loading new transformers are needed depending on the utility they may pay for that upgrade or ask you to pay. The only way to know about the transformer and service drop to the meter is to ask the utility. You may be able to read the size on your existing service conductors (feeder) but I would bet that it will need to be upsized going from 100 to 200.