No, logging in directly to a resource mailbox is not a supported scenario, you need to use Full access permissions and a "regular" account. An acceptable workaround might be to "publish" the calendar and load the resulting web page:
Set-MailboxCalendarFolder TV:\Calendar -PublishEnabled $true
Get-MailboxCalendarFolder TV:\Calendar | select -ExpandProperty PublishedCalendarUrl
http://outlook.office365.com/owa/calendar/******@domain.com/b6d030b90bd442359df08bb0bd0615594219520892717264596/calendar.html
Alternatively, you can access the data programmatically/expose it in your preferred way.