Lanarkshire to Dover

JacquiPat

Heading to Dover with a planned stopover at Great Ponton on A1. According to Via Michelin the jouney should take 3 hours 40 mins from here to Dover.  If we leave at 8am on a Tuesday, would 5 hours be sufficient to make it on time for a 1pm crossing? We don't
have experience of driving A1 this far south and I am a bit worried about traffic during these times on an unfamilliar road. Thanks in advance for advice. Jacqui