Just that, really.
Not in ££ obviously, but as % of disposable income and with no known prospect of change in circumstances (for better or worse)
We're faced with what feels like a once-in-a-lifetime opportunity and in need of perspective on whether we are being unduly cautious or utterly reckless 
(and I know it's v much a "how long is a piece of string" type question but genuinely interested to know others' opinions)