I highly doubt he will die during the digvijay....
Because.....
1. All of Prithvi's friends are alive until after Digvijay, because after Digvijay, he establishes the paanch kul, in which all of his friends are present, to look into all the matters of administration.
2. I haven't really read this anywhere, but my mom claims, that Sanjam will get married to Chamki right when Prithvi gets married to Sanyogita. She says that Sanyogita will send Prithvi information abt the Swayamvar thru Chamki...and Chamki will not come back from ajmer....because she thinks that if she comes back, Jaichand will kill her for being a traitor to her kingdom....so she stays in ajmer...falls in love with sanjam....and marries him....abt the same time prithvi marries sanyo....(This is based on what my mom told me....she read the gujarati version of prc....prc...ek amar katha???...i think....)