We have had a lot of customers make some REALLY long maps by doing things section at a time and then combining them in a Location Map. It is really the only way to do it with high resolution and having it go all over the place.
One things you really want to keep in mind is that Maps Made Easy doesn't like long skinny jobs. Once the output files get over 65k in resolution the outputs switch over to BigTiff images which are a real pain to work with.
To work around this, know your GSD and then take care to not create any jobs that are wider in longitude or taller in latitude that will fit in a 62k or so limit.
For example, you want 3 cm/px GSD. 62,000 * 3 cm is 1.86 km. Make sure that your job isn't wider or taller than 1.86km to stay within our processing limits.
We hope to add a special mapping mode for linear jobs like this in the future.