i have a MILP with ~3000 binaries, 300000 continuous variables and ~1MM constraints. I am trying to solve this on the VM how long could it potentially take on a 16 core 128 gig machine? also what are the general limits of creating problems using  pulp that cplex solver can handle on such a machine? any insights would be appreciated
The solution time is not just a function of the number of variables and equations. Basically, you just have to try it out. No one can predict how much time is needed to solve your problem.
scaling MILP using pulp and cplex