45 meters is quite long for a _stagebox_ (sorry couldn't resist...)
To answer your question: I've been working in first class musical sound a lot. The multicores from the radios to the FOH were often 100m long (line level signal) and this was no problem. Mic cables from the orchestra pit were about 50m including patch cables to the console.
Sure the shorter cable runs can be the better. At least use high quality multicore cable.
As long as i can make decent recordings, needed the length as i do alot of mobile recording so the control room/area will need to be a good distance away if the enue doesn't have sound insulation etc. BTW; tried hooking up the lexicon to the ins and outs of the motu and it works a treat (forgot i could configure the sends on the virtual tracks in logic)!! Will probably bypass the desk apart from monitoring purposes and when im recording. Thanks for your help!