Vacation Ideas With A Toddler - Boston To Canada

Hi all,
We are planning a vacation with our super active toddler and planning to go to Quebec City from Boston. We were thinking of skipping Montreal to keep trip relaxing. Please suggest .

1. I think Road trip will be better with kid. Flights are expensive. Trains/Bus are not fast or direct.
2. We have 4 days. We were thinking just to do QC, ( skip Montreal ?)so we do not come crashing to hotel room and do not come late. We might stay overnight near border on Maine Border on way to QC. Suggestions?
3. What to cover in QC? Kid friendly places?
4. Where to stay in QC or US- Canada border? Also I will have to cook in hotel room for LO. so will book kitchenette if possible.