Internship to full time investment banking

I have just completed a 5 week investment banking internship at a boutique bank. This bank could be classed as an elite boutique and it has a very strong reputation with many high profile deals. It has previously been in the news about its strong deal flow.
There has been a little down turn and I didn't get a return offer due to lack of work.
Also they usually only take on people with around 4-5 years of solid experience.

How hard will it be for me to leverage this internship into a full time role elsewhere in investment banking?

Is getting a full time offer after an internship in investment banking as hard as it is to get the initial internship?

I ask this because I have started to explore back office careers but investment banking is my first choice.