You can simply save MHTML page to PDF document using the default printing function in web browsers.
Convert Web page archive to Adobe Portable document format.
We have found 2 software records in our database eligible for .mhtml to .pdf file format conversion.
Microsoft Windows software - convert mhtml to pdf on Windows
A popular free web browser from Mozilla
Convert from mhtml file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned mhtml to pdf. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A popular Internet browser from Google