We have had our van there now three times, last ime we stayed for just over 3 months, next time thinking about 6 months.
Yes it is costly on the ferry…..but the longer you can stay the more justification you can get on the charges.
The costs are FAR OUTWAYED but the shear delights you will see & experience.
Do consider staying more ‘than a few weeks’
Have a great time, travel safe ,
Tony