At Christmas I travelled by Eurotunnel but stayed on Calais side in Aire on Cite shopping complex. Bit noisy as it is next to trains but plenty of space. There and back arrived at the Aire about midnight. Advantage is that I can travel after work on Friday, cross the channel and then get early start on French motorways.
You probably are aware but the French motorway service areas have been closed around Calais.
Also when last over there in February there wasn't much difference in Diesel prices compared to UK. The falling Sterling/Euro rate being the reason. Supermarket prices, 1.30 Euros Motorway more expensive.
They allow you to park up at the ferry terminal in Portsmouth, I think you need to arrive after the last ferry check in of the day so around 10pm onwards.