We also have the 3 package which is fine but are tied in to a 24 month contract.
As the caravan season is only 9 months I will be paying for 12 months each year but can use the router at home for the 3 months out of season.
When the contract expires I will switch to SMARTY unlimited data sim only which piggy backs the 3 network so service is identical but there is no contract to be tied in to. They do a monthly pay as you go for about £20 per month.
Most people on my site swear by EE but this is much dearer for no extra benefit in my eyes.
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