If an organization wants to carry out maintenance on temporary fire bases and it is not a case of AOG or occasional maintenance, that is, if you want to make use of fixed facilities (warehouse, office, etc.) and it is estimated that the use will be greater than 40 days, you must request the opening of a line station for each location.  
Otherwise, support could be provided by a mechanic on board / traveling in a van if the need to request opening of installation (although defining in the EOM the necessary procedures).

EASA ANSWER:

Line stations staffed with one person (the certifying staff) contracted externally may require attention, in particular ensuring:

Yes, provided that it has continued to apply the requirements of point 2.8 of AMC 2 of 145.A.50(d) to re-incorporate the component into the EASA system. 

The EOM Evaluation Guide indicates, in the functions of the Compliance Control Officer in section 1.4.2, "7". It is responsible for the preparation of standard practices and procedures (including the EOM and associated procedures) for use within the organization, and ensures their adequacy with respect to Part 145. Could the Maintenance Manager perform this function and then the Compliance Control Manager give the go-ahead?

As provided in point CAMO.A.125(d)(3), a CAMO may organise the performance of limited continuing airworthiness tasks with any subcontracted undertaking, working under its Management System, which shall be included in its certificate of approval (AC-CAMO-P01-F14).
Tasks that can be outsourced include reliability control and engine health control (reliability monitoring & engine health monitoring). 

“Details of maintenance work performed” according to GM M.A.305(g) are the records that must be maintained by the person or organisation responsible for the continuing airworthiness of the aircraft in accordance with M.A.201 in order to be able to fulfil its obligations under Part M. They are only part of the records referred to in points CAO.A.090(a) or 145.A.55(a).
Maintenance organizations must keep all detailed records to demonstrate that they have worked in accordance with their respective requirements and procedures.

Yes, regardless of owner/operator approvals and scope, you have the option to sign a contract with a CAMO. The important thing is that continued airworthiness is managed by an appropriate CAMO.

Electric load analysis (ELA) is provided by the aircraft manufacturer to the operator.
These data are part of the ICAs (see AMC to Appendix H, H25.5 Instructions for continuing airworthiness applicable to point 5 of the EWIS). Changes to ICAs are changes to the type certificate that must be approved in accordance with Part 21.
Where relevant, a change or modification should contain a difference sheet for ELA, so that the operator can update the current ELA.

The standard does not impose a "basic" or "generic" maintenance program; however, Chapter 1.2 of the CAME should describe how the organisation will develop the AMP. 
The organization must define the means to demonstrate that they are competent for the management that is intended to be carried out. Certain elements, such as the IT tool to manage the AMP, access to applicable technical documentation and/or staff experience in AMP matters, can contribute to achieving this objective.

In principle, to maintain the privilege as a PRA in a CAMO Y, the experience demonstrated by performing work on a CAMO X will also be considered valid.