Having multiple free accounts would be mistaking their generosity, for the notion that everything is free. You should realize that nothing is. Someone is paying for the server, the electricity, the air condition, the time to repair, make changes, monitor, secure everything. Please do not take advantage of their generosity to suit your personal desires.
If you need more space, just fork over the $6 a month (or the $20 development package) and get it. But really, there's enough space to get something up for multiple sites. If you've used it all, then you're probably doing something wrong, or you should be making money from it so that you can afford to go to a paid server.