Hi, I have applied something like that in Odoo 11 and I think it will work on other versions.

To resize the logo in invoice report only, you need to pass value through context from invoice report and then check it in the external layout bold template.

I have added change_logo_size Boolean context value from invoice report and set it to true as below:

<template id="report_invoice_document_logo" inherit_id="account.report_invoice_document">
    <xpath expr="//t[@t-call='web.external_layout']" position="before">
        <t t-set="o" t-value="o.with_context(change_logo_size= True)"/>
    </xpath>
</template>

Then in the inheritance of external layout bold, I have checked the value from the context and if it's true then apply the replace for image, otherwise leave it as its:

<template id="external_layout_bold_ksp" inherit_id="web.external_layout_bold">
    <xpath expr="//div[@t-attf-class='header o_company_#{company.id}_layout']/div/div/div/img" position="replace">
        <t t-if=" o and o.env and 'change_logo_size' in o.env.context and o.env.context.get('change_logo_size',False)">
            <img t-if="company.logo" style="max-width: 350px;max-height: 190px;"
                 t-att-src="image_data_uri(company.logo)" alt="Logo"/>
        </t>
        <t t-else="">
            <img t-if="company.logo" t-att-src="image_data_uri(company.logo)" alt="Logo"/>
        </t>
    </xpath>
</template>