There are still some other things that can be done federally to help. If they change the size of the house (determined by legislation not constitution), it also changes electoral votes for states. Electoral votes are based on house + senate seats per state

On its own that makes the electoral college much closer to representing the population of each state

I would also presume it likely would also make the popular vote compact way closer or cross the needed majority of electoral votes. Though I haven’t done or seen any analysis on that directly so not 100% sure because the ways seats are appropriated can be funky and non-linear