How to overcome the situation of having lack of content and not updating regularly?
I think this is very common for many businesses.
You may try following:
Generally, in hospitality industry businesses have more quality photos. So, even if you are not updating content (text) regularly, you can update photos which is simple and quick and still, it will give some signal towards freshness.
You may create image slideshow video with key features and upload it on YouTube with an appropriate link.
As mentioned in the comment, worth adding testimonials.
Make use of Google Plus, do a regular G+ post with good photos and have a bit longer (text) post and place the appropriate link.
Encourage customer to write reviews on third party sites, particularly Google local and this will play an important role to boost your ranking naturally.
There are may more ideas, you just need to think in a creative way.