Xiao, I try to re-pot the large containers in the spring. Seems your idea of drying them all out to induce dormancy and then re-pot is a good idea. Sometimes in past years I may not of had time to re-pot all the pots; when that happened the not changed pots didn't yield as many viable tubers as the pots that were re-potted, but both put on a good show.
There's a comment at the bottom of the page in this link -
Gloriosa Lily (Gloriosa superba 'Rothschildiana')
about re-potting gloriosas.
They're likely to be all tangled up in the soil and are very brittle, so be careful not to break any when you un-tangle them. Here's an example of the tangled -
and here's my carsonii -
