My SIM only plan with EE is up at the end of this month but if you don't renew and agree a new contract, your plan should stay as it is but it'll switch to a 30 day rolling plan.
I pay £12 p/m for 30gb of data which I don't use anywhere near
There's an offer on there for me for £16 p/m, unlimited data, 24m contract. Tempted to just take that so I know I'm locked in for two years but might just try the PAC code request so retentions call me and see what they offer