Rams might need to draft two tackles in the draft if they do not extend Jackson, but if they do extend him, then I still would draft two. Need a replacement RT for Havenstein and a swing tackle too.
I think what drives the offseason OT strategy will be the status of Matthew Stafford. And to go a step further how he performs in the playoffs will likely factor in there as well.
If the Rams elect to stay with Stafford as QB1 then they will keep both Jackson & Havenstein and draft a swing OT. This is because to do more than that is not the most efficient use of their resources to maximize a title run.
If the Rams elect to move on from Stafford as QB1 then a deeper approach on offense is likely. In other words then they may not pay Jackson and instead try to tag & trade him and/or move up to take a LT, as well as possibly Hav's replacement in rounds 3/4. This is because OTs require time to settle in and they might miss on one or both of them, so only way this happens is if they elect to blow up the offense starting with the QB1 spot.
Now I suppose it's also possible Stafford retires or whatever and the Rams chase another QB like say Darnold. But the OTs will follow the QB certainty. Which is to say if they were to add Darnold after Stafford retires it would be the same as making a run with Stafford in that they would be unlikely to blow up the tackle spots for fear of fucking their ability to contend.
"That's my boy!"
~ OS