Now is the time. The 2/3 of the House and Senate isn't going to happen because they are too evenly split. However, with 2/3 of the states in Republican hands a convention of states could be called. 3/4 of the states would still need to pass any proposed amendment which would still be difficult. Maybe a congressional term limit or balanced budget amendment?
At a CoS rules must be made to prevent big states like NY and CA from running roughshod over the small ones. Such as each state may send 5 representative but has only one vote on whether to send amendments to the states and individual amendments only. No package deals.